Re: Playing with HP2640B
We just dumped the enhanced character ROMs from a HP2645. 8k bipolar mask ROMs, 90 ns (they need to be fast since they are used as video RAM really). I read them on the Data IO using their PROM equivalent, AMD 27S181. The microvectors sets (line set and large character sets) are 9 bits. The 9th bit comes out on pin 18 in place of an enable pin in the more conventional 8-bit version. I read them in two passes, wiring the pin for bit 9 in place of bit 8 pin the second time around. 9-bit mask ROMs! Why not 5-legged pigs while you are at it. Then we found that even HP had misgivings about their weird 9-bit ROM choices, must have cost a fortune. Carl had a later rev board that had 8-bit version of the microvector sets, where the board has electronics to create an emulated 9th bit by shifting all the bits out and duplicating bit 0. Better yet, we burned some new 8-bit bipolar PROMs (Harris 7681), emulated the bit shifting on my older rev of the board by cross-wiring, and added new large character sets to my terminal! That was fun. Marc On Dec 5, 2017, at 1:36 PM, Brent Hilpert via cctalkwrote: On 2017-Dec-05, at 1:20 PM, Brent Hilpert via cctalk wrote: >> On 2017-Dec-05, at 1:08 PM, Mattis Lind wrote: >> 2017-12-05 20:44 GMT+01:00 Brent Hilpert via cctalk : >>> On 2017-Dec-05, at 9:14 AM, Mattis Lind via cctalk wrote: >> Does the 27S82 have any equivalents that I could look up instead in the device list? >> >>> FWIW, 27S82 is listed in the 1982 IC Master as >> >>> AM27S82M: TTL 1024*8 ROM, 275nS access, OC outputs, 24 pin, 5V supply >> >>> So half the size of a 2716. >>> The book lists PROMs and ROMs separately, so it was probably >>> mask-programmed. >>> (M would be for mil temp going by other AMD numbers.) >> >> I would think bipolar PROM since rest of the AMD 27S series were bipolar >> PROMs. I will check this weekend if I can find an old AMD databook. > > The ref did specify it as TTL, so yes, bipolar. Oh, as for being PROM vs ROM, I'm just going by the way things are listed in the ref. It lists different 27Sxx devices under PROM vs ROM, for example 27S180, 27S181 are 1024*8 listed under PROM, but 27S80, 27S81, 27S82, 27S83 are 1024*8 listed under ROM. It's possible they're mis-listed of course, but manufacturers often did make equivalent devices as both fusible and mask, I don't know what AMD did for series names in that regard.
Re: Playing with HP2640B
On 2017-Dec-05, at 1:20 PM, Brent Hilpert via cctalk wrote: > On 2017-Dec-05, at 1:08 PM, Mattis Lind wrote: >> 2017-12-05 20:44 GMT+01:00 Brent Hilpert via cctalk: >>> On 2017-Dec-05, at 9:14 AM, Mattis Lind via cctalk wrote: >> Does the 27S82 have any equivalents that I could look up instead in the device list? >> >>> FWIW, 27S82 is listed in the 1982 IC Master as >> >>> AM27S82M: TTL 1024*8 ROM, 275nS access, OC outputs, 24 pin, 5V supply >> >>> So half the size of a 2716. >>> The book lists PROMs and ROMs separately, so it was probably >>> mask-programmed. >>> (M would be for mil temp going by other AMD numbers.) >> >> I would think bipolar PROM since rest of the AMD 27S series were bipolar >> PROMs. I will check this weekend if I can find an old AMD databook. > > The ref did specify it as TTL, so yes, bipolar. Oh, as for being PROM vs ROM, I'm just going by the way things are listed in the ref. It lists different 27Sxx devices under PROM vs ROM, for example 27S180, 27S181 are 1024*8 listed under PROM, but 27S80, 27S81, 27S82, 27S83 are 1024*8 listed under ROM. It's possible they're mis-listed of course, but manufacturers often did make equivalent devices as both fusible and mask, I don't know what AMD did for series names in that regard.
Re: Playing with HP2640B
On 2017-Dec-05, at 1:08 PM, Mattis Lind wrote: > 2017-12-05 20:44 GMT+01:00 Brent Hilpert via cctalk: > >On 2017-Dec-05, at 9:14 AM, Mattis Lind via cctalk wrote: > > >> Does the 27S82 have any equivalents that I could look up instead in the > >> device list? > > >FWIW, 27S82 is listed in the 1982 IC Master as > > > AM27S82M: TTL 1024*8 ROM, 275nS access, OC outputs, 24 pin, 5V > > supply > > >So half the size of a 2716. > >The book lists PROMs and ROMs separately, so it was probably mask-programmed. > >(M would be for mil temp going by other AMD numbers.) > > I would think bipolar PROM since rest of the AMD 27S series were bipolar > PROMs. I will check this weekend if I can find an old AMD databook. The ref did specify it as TTL, so yes, bipolar.
Re: Playing with HP2640B
2017-12-05 20:44 GMT+01:00 Brent Hilpert via cctalk: > On 2017-Dec-05, at 9:14 AM, Mattis Lind via cctalk wrote: > > > > Looking more into this document revelas that it covers three boards > > 02640-60009, 02640-60088 and 02640-60112. > > > > Now I had the idea of dumping the character ROM as well. But what is a > AMD > > 27S82? I cannot really find a datasheet online. From the schematics above > > it looks not too much off from standard 2716 EPROM with pin 19 (A10) as > E3 > > , pin 21 (VPP) as /E1. But my Data I/O 29B does not seem to be > compatible > > with 27S82 and as pin 21 is active low it gives that a 2716 setting in > the > > programmer (reader) won't work. > > > > Does the 27S82 have any equivalents that I could look up instead in the > > device list? > > FWIW, 27S82 is listed in the 1982 IC Master as > > AM27S82M: TTL 1024*8 ROM, 275nS access, OC outputs, 24 pin, 5V > supply > > So half the size of a 2716. > The book lists PROMs and ROMs separately, so it was probably > mask-programmed. > (M would be for mil temp going by other AMD numbers.) > > I would think bipolar PROM since rest of the AMD 27S series were bipolar PROMs. I will check this weekend if I can find an old AMD databook. I do have the "Schottky and Low-Power Schottky Bipolar memory, Logic and Interface" somewhere. https://drive.google.com/file/d/0B-rp4vyPPYu1Z3d6MkxRQ1NlVXc/view?usp=sharing I traced the card to understand if the board actually matched the schematics and it did. Pin 18 was NC and the it was possible to read the chip with my trusty Data IO 29B as a 2732 and just use the first 1024 bytes out of it. The resulting files are here for those who like to preserve them: http://storage.datormuseum.se/u/96935524/Datormusuem/HP2640B/hp2640b-chargen-1816-0612.hex http://storage.datormuseum.se/u/96935524/Datormusuem/HP2640B/hp2640b-chargen-1816-0613.hex
Re: Playing with HP2640B
On 2017-Dec-05, at 9:14 AM, Mattis Lind via cctalk wrote: > > Looking more into this document revelas that it covers three boards > 02640-60009, 02640-60088 and 02640-60112. > > Now I had the idea of dumping the character ROM as well. But what is a AMD > 27S82? I cannot really find a datasheet online. From the schematics above > it looks not too much off from standard 2716 EPROM with pin 19 (A10) as E3 > , pin 21 (VPP) as /E1. But my Data I/O 29B does not seem to be compatible > with 27S82 and as pin 21 is active low it gives that a 2716 setting in the > programmer (reader) won't work. > > Does the 27S82 have any equivalents that I could look up instead in the > device list? FWIW, 27S82 is listed in the 1982 IC Master as AM27S82M: TTL 1024*8 ROM, 275nS access, OC outputs, 24 pin, 5V supply So half the size of a 2716. The book lists PROMs and ROMs separately, so it was probably mask-programmed. (M would be for mil temp going by other AMD numbers.)
Re: Playing with HP2640B
On Tue, 5 Dec 2017, Mattis Lind wrote: 2017-12-05 16:51 GMT+01:00 Mike Loewen via cctalk: On Tue, 5 Dec 2017, Mattis Lind wrote: 2017-12-05 16:26 GMT+01:00 Mike Loewen via cctalk : On Tue, 5 Dec 2017, Mattis Lind via cctalk wrote: While going through the HP2640B I found two boards which I cannot find relevant schematic and description for, the 02640-60009 Display Memory Access Module and the 02640-60088 Display Timing Module. Anyone has more info on these? The manual for the 02640-60088 is here: http://www.hpmuseum.net/document.php?hwfile=2542 Looking more into this document revelas that it covers three boards 02640-60009, 02640-60088 and 02640-60112. Now I had the idea of dumping the character ROM as well. But what is a AMD 27S82? I cannot really find a datasheet online. From the schematics above it looks not too much off from standard 2716 EPROM with pin 19 (A10) as E3 , pin 21 (VPP) as /E1. But my Data I/O 29B does not seem to be compatible with 27S82 and as pin 21 is active low it gives that a 2716 setting in the programmer (reader) won't work. Does the 27S82 have any equivalents that I could look up instead in the device list? I couldn't find that part number either, but I dumped the PROMs on my 2647A Control Memory PCAs, which use an AMD AM9216BDC PROM. It appears to be set up the same way as you describe. I hand-wired an adapter to plug into my 29B, and told it that I was reading a 2716. The datasheet for the AM9216BDC is in the AMD MOS/LSI Data Book: http://bitsavers.informatik.uni-stuttgart.de/components/amd/_dataBooks/1980_AMD_MOS_LSI_Data_Book.pdf Mike Loewen mloe...@cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/
Re: Playing with HP2640B
2017-12-05 16:51 GMT+01:00 Mike Loewen via cctalk: > On Tue, 5 Dec 2017, Mattis Lind wrote: > > 2017-12-05 16:26 GMT+01:00 Mike Loewen via cctalk : >> >> On Tue, 5 Dec 2017, Mattis Lind via cctalk wrote: >>> >>> While going through the HP2640B I found two boards which I cannot find >>> relevant schematic and description for, the 02640-60009 Display Memory Access Module and the 02640-60088 Display Timing Module. Anyone has more info on these? >>>The manual for the 02640-60088 is here: >>> >>> http://www.hpmuseum.net/document.php?hwfile=2542 >> >> Looking more into this document revelas that it covers three boards 02640-60009, 02640-60088 and 02640-60112. Now I had the idea of dumping the character ROM as well. But what is a AMD 27S82? I cannot really find a datasheet online. From the schematics above it looks not too much off from standard 2716 EPROM with pin 19 (A10) as E3 , pin 21 (VPP) as /E1. But my Data I/O 29B does not seem to be compatible with 27S82 and as pin 21 is active low it gives that a 2716 setting in the programmer (reader) won't work. Does the 27S82 have any equivalents that I could look up instead in the device list? > >>> >> >> Thanks! Those numbers fooled me. Some time the number seems to correspond >> a >> bit between the number on the board and some times not. >> > >The Data Terminal Technical Information Package contains a > cross-reference for PCAs and Module numbers. Unfortunately, it doesn't > list the 02640-60009. > > http://www.hpmuseum.net/document.php?hwfile=2541 > > > > Mike Loewen mloe...@cpumagic.scol.pa.us > Old Technology http://q7.neurotica.com/Oldtech/ >
Re: Playing with HP2640B
On Tue, 5 Dec 2017, Mattis Lind wrote: 2017-12-05 16:26 GMT+01:00 Mike Loewen via cctalk: On Tue, 5 Dec 2017, Mattis Lind via cctalk wrote: While going through the HP2640B I found two boards which I cannot find relevant schematic and description for, the 02640-60009 Display Memory Access Module and the 02640-60088 Display Timing Module. Anyone has more info on these? The manual for the 02640-60088 is here: http://www.hpmuseum.net/document.php?hwfile=2542 Thanks! Those numbers fooled me. Some time the number seems to correspond a bit between the number on the board and some times not. The Data Terminal Technical Information Package contains a cross-reference for PCAs and Module numbers. Unfortunately, it doesn't list the 02640-60009. http://www.hpmuseum.net/document.php?hwfile=2541 Mike Loewen mloe...@cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/
Re: Playing with HP2640B
2017-12-05 16:26 GMT+01:00 Mike Loewen via cctalk: > On Tue, 5 Dec 2017, Mattis Lind via cctalk wrote: > > While going through the HP2640B I found two boards which I cannot find >> relevant schematic and description for, the 02640-60009 Display Memory >> Access Module and the 02640-60088 Display Timing Module. Anyone has more >> info on these? >> > >The manual for the 02640-60088 is here: > > http://www.hpmuseum.net/document.php?hwfile=2542 Thanks! Those numbers fooled me. Some time the number seems to correspond a bit between the number on the board and some times not. > > > Mike Loewen mloe...@cpumagic.scol.pa.us > Old Technology http://q7.neurotica.com/Oldtech/ >
Re: Playing with HP2640B
On Tue, 5 Dec 2017, Mattis Lind via cctalk wrote: While going through the HP2640B I found two boards which I cannot find relevant schematic and description for, the 02640-60009 Display Memory Access Module and the 02640-60088 Display Timing Module. Anyone has more info on these? The manual for the 02640-60088 is here: http://www.hpmuseum.net/document.php?hwfile=2542 Mike Loewen mloe...@cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/
Re: Playing with HP2640B
I have now dumped the firmware from the HP2640B terminal. Since the EA4900 ROMs are not much like normal EPROMs in regards to pinout and supply voltages I resorted to use a logic analyzer to dump the contents of the ROM simply by parsing out the ROM accesses while the terminal did the selftest. It took a quite many dumps to get the full firmware out of it since my analyzer HP16550 boards have limited storage. Someone that has a HP16555A board to sell? http://storage.datormuseum.se/u/96935524/Datormusuem/HP2640B/2640.hex One file for all four ROMs. The good thing attaching the analyzer was that it helped me to find the two bad 2102 chips on one of the memory boards. Now I get the full 5kKbytes. While going through the HP2640B I found two boards which I cannot find relevant schematic and description for, the 02640-60009 Display Memory Access Module and the 02640-60088 Display Timing Module. Anyone has more info on these? With the firmware downloaded I tried to investigate why the small Diagnostic Download example described here: http://computermuseum.informatik.uni-stuttgart.de/dev_en/hp2644/diag.html The example tries to call address 315 octal, but the firmware I dumped has a HLT instruction at this location which explains why the terminal hangs completely. The HP2644 firmware is most likely different from the HP2640B firmware. http://www.datormuseum.se/peripherals/terminals/hp-264x
Re: Playing with HP2640B
> Wow! Excellent job Mattis > I have seen that HP2640 when it still was in bad shape. The HP2640, > that I have, has many tiny spots on the screen. Your “result after” > really looks fantastic. Thanks Henk! I have a few more screens that need fixing. The most difficult will be the Tek 4016. So I need to do some practice before that one. > What’s not clear to me, after removing the old “protection” sheet, did > you apply some new “protection” sheet, or leave the tube “as-is” ? > I doubt whether that “protection” sheet would really help much if > the tube would implode (for whatever miraculous reason) … No, I didn't add anything between the crt and the glass. If it actually is a protective shield then of course there is not at all the same protection afterwards. But as Christian Corti mentioned it might just be an etched glass to remove reflections. I know at the RICM when doing the same thing on a DEC VR14 they added a sheet of lexan between the crt and the glass. I think Michael Thompson can tell more about this. > > Henk > /Mattis
RE: Playing with HP2640B
Van: Mattis Lind via cctalk<mailto:cctalk@classiccmp.org> Verzonden: vrijdag 17 november 2017 11:52 Aan: David Collins<mailto:davidkcolli...@gmail.com>; General Discussion: On-Topic and Off-Topic Posts<mailto:cctalk@classiccmp.org> Onderwerp: Re: Playing with HP2640B The screen on my HP2640 had degenerated quite far. It was only a spot in the middle, 2 by 4 inch, that still attached the glass to the CRT. I used a thin fish fillet knife to dig through the remaining glue. Before https://scontent-arn2-1.xx.fbcdn.net/v/t1.0-9/23622163_10155696765784985_6518064439030378363_n.jpg?oh=44cbf7f7f00d6e25155c208124e20a38=5AA7349D The result after: https://scontent-arn2-1.xx.fbcdn.net/v/t1.0-9/23621971_10155696757184985_1959733265676657917_n.jpg?oh=36a20689c0fb5a16de7fc4df138a40e0=5A9993B1 Anyhow, I researched the glue a bit. The glue is, as far as I understand, PVAc (PolyVinylAcetate, sometimes also known as PVA). PVAc is not soluble in water. It takes quite high temperature to melt it. However PVAc is soluble in many esters. I bought some Butylacetate. It dissolves sample bits of glue from HP2640 quite well and rapidly. Butylacetate has quite high boiling temperature (about 120 degrees centigrade) and thus does not evaporate that quickly. So my idea is now to test on a 2645 screen or VR201 screen by adding some butylacetate and seal with some thin plastic wrap foil and let it dissolve a bit. Then use the fish fillet knife again and repeat the process. /Mattis Wow! Excellent job Mattis I have seen that HP2640 when it still was in bad shape. The HP2640, that I have, has many tiny spots on the screen. Your “result after” really looks fantastic. What’s not clear to me, after removing the old “protection” sheet, did you apply some new “protection” sheet, or leave the tube “as-is” ? I doubt whether that “protection” sheet would really help much if the tube would implode (for whatever miraculous reason) … Henk
Re: Playing with HP2640B
On Fri, 17 Nov 2017, David Collins wrote: Christian do you know the gauge of the wire you used ? And the current? It was a wire for cutting polystyrene blocks. The current was a fews amperes, I think, driven off a bench power supply. Christian
RE: Playing with HP2640B
I did it by heating the crt to about 50-60 degrees celsius and used a putty-knife. https://www.flickr.com/photos/hp-fix/albums/72157689357633754 The photos are from a Philips P2000M system but I did it the same way with my 264X terminals and 9845's systems. It takes about half an hour to heat and separate the screen from the crt . -Rik > The screen on my HP2640 had degenerated quite far. It was only a spot in the > middle, 2 by 4 inch, that still attached the glass to the CRT. I used a thin > fish fillet > knife to dig through the remaining glue. > > Before > > https://scontent-arn2-1.xx.fbcdn.net/v/t1.0- > 9/23622163_10155696765784985_6518064439030378363_n.jpg?oh=44cbf7f7f > 00d6e25155c208124e20a38=5AA7349D > > The result after: > > https://scontent-arn2-1.xx.fbcdn.net/v/t1.0- > 9/23621971_10155696757184985_1959733265676657917_n.jpg?oh=36a20689 > c0fb5a16de7fc4df138a40e0=5A9993B1 > > > Anyhow, I researched the glue a bit. The glue is, as far as I understand, PVAc > (PolyVinylAcetate, sometimes also known as PVA). PVAc is not soluble in water. > It takes quite high temperature to melt it. However PVAc is soluble in many > esters. I bought some Butylacetate. It dissolves sample bits of glue from > HP2640 > quite well and rapidly. Butylacetate has quite high boiling temperature (about > 120 degrees centigrade) and thus does not evaporate that quickly. So my idea > is > now to test on a 2645 screen or VR201 screen by adding some butylacetate and > seal with some thin plastic wrap foil and let it dissolve a bit. Then use the > fish > fillet knife again and repeat the process. > > /Mattis
Re: Playing with HP2640B
The screen on my HP2640 had degenerated quite far. It was only a spot in the middle, 2 by 4 inch, that still attached the glass to the CRT. I used a thin fish fillet knife to dig through the remaining glue. Before https://scontent-arn2-1.xx.fbcdn.net/v/t1.0-9/23622163_10155696765784985_6518064439030378363_n.jpg?oh=44cbf7f7f00d6e25155c208124e20a38=5AA7349D The result after: https://scontent-arn2-1.xx.fbcdn.net/v/t1.0-9/23621971_10155696757184985_1959733265676657917_n.jpg?oh=36a20689c0fb5a16de7fc4df138a40e0=5A9993B1 Anyhow, I researched the glue a bit. The glue is, as far as I understand, PVAc (PolyVinylAcetate, sometimes also known as PVA). PVAc is not soluble in water. It takes quite high temperature to melt it. However PVAc is soluble in many esters. I bought some Butylacetate. It dissolves sample bits of glue from HP2640 quite well and rapidly. Butylacetate has quite high boiling temperature (about 120 degrees centigrade) and thus does not evaporate that quickly. So my idea is now to test on a 2645 screen or VR201 screen by adding some butylacetate and seal with some thin plastic wrap foil and let it dissolve a bit. Then use the fish fillet knife again and repeat the process. /Mattis
Re: Playing with HP2640B
Christian do you know the gauge of the wire you used ? And the current? Maybe I should try that approach again! David Collins > On 17 Nov 2017, at 8:09 pm, Christian Corti via cctalk >wrote: > >> On Thu, 16 Nov 2017, CuriousMarc wrote: >> What did you do for the screen mold? Hot wire method to separate CRT from >> implosion window? Put the CRT in a hot water bath? Chip at the glue? Marc > > What we did on one of our 2645 terminals was the hot wire method. We then > attached the "implosion" window to the inner of the case. > > BTW is it really an implosion protection? I don't think so because since the > 60s, practically all CRTs have a so-called "integral implosion protection" > (thick glass on the front and metal band around the edge). I think it is just > an anti-glare filter glass. OTOH American CRTs may be completely different in > this aspect compared to European ones. > > Christian
Re: Playing with HP2640B
Marc, in addition to Mattis’ forthcoming reply, my recent experience with a moldy 2624A was that the hot wire method was very poor. Too hard to get the wire in, didn’t melt the ‘glue’ very well, smelly. Gave up when the wire broke. What worked best for me was a flat blade screwdriver that was small enough to sit sideways in the gap between the front glass and the tube. I sliced sections of the glue and picked them out with a hook. I also squirted in a combination of RP7 and household cleaner but not sure either did anything other than lubricate the surfaces - they may have helped lift the glue a bit. My ‘glue’ was like a layer of silicon rubber which hung on for as long as possible but I got it all off without any damage. I replaced the front glass and held it on with a bead of black silicon rubber used for shower glass. I spaced it from the tube with pieces of wire around the edges and pulled them out when the silicon dried. Worked well for me but keen to hear how Mattis went. I didn’t try the hot water soak but it would probably help. David Collins > On 17 Nov 2017, at 6:12 pm, CuriousMarc via cctalk> wrote: > > What did you do for the screen mold? Hot wire method to separate CRT from > implosion window? Put the CRT in a hot water bath? Chip at the glue? > Marc > > > > On Nov 15, 2017, at 11:48 AM, Mattis Lind via cctalk > wrote: > > I have been working on a HP 2640B terminal. It was mostly about fixing the > "screen mold" problem and cleaning up the liquids that had been seeping out > from the screen down into the bottom. > > The small coaxial wire that connects the 4.9152 MHz clock signal form the > power supply (never seen a crystal controlled SMPSU before!) to the > backplane was broken off, but after fixing that the terminal worked fine. > Just needed some adjustment to the brightness. > > With the correct terminfo installed it worked quite well as a serial > terminal to a Linux box. > > Then I tried the short 8008 programs that Christian Corti pointed to > > http://computermuseum.informatik.uni-stuttgart.de/dev_en/hp2644/diag.html > > and > > ftp://computermuseum.informatik.uni-stuttgart.de/hp/hp2644 > > I tried both a couple of times. The terminal enter the LOADER mode but just > hangs completely at the end. I tried different baudrates but no difference. > > The selftest STATUS line tell me 40<802 which should indicate that there > are 4k memory in the terminal. However there should be 5k since there is > one 4k board and one combined control store and 1 k RAM board. Maybe there > is a fault in the 1k SRAM? The terminal doesn't complain though. > > Regardless, the programs listed either starts at adress 3 or 36000 > which should then be within the available space. > > The question is, should these program work for the HP2640B as well? It has > a 8008 but my guess is that the firmware is different from the 2644. What > is the joint experience regarding this? Has anyone ran these small programs > above on a HP2640B? > > The HP 2640B firmware consists of four EA 4900 ROM chips which annoyingly > are not anything like normal EPROMs. So dumping will need special > considerations. > > Has anyone dumped the HP 2640B firmware already? I didn't find it on > bitsavers. > > /Mattis
Re: Playing with HP2640B
On Thu, 16 Nov 2017, CuriousMarc wrote: What did you do for the screen mold? Hot wire method to separate CRT from implosion window? Put the CRT in a hot water bath? Chip at the glue? Marc What we did on one of our 2645 terminals was the hot wire method. We then attached the "implosion" window to the inner of the case. BTW is it really an implosion protection? I don't think so because since the 60s, practically all CRTs have a so-called "integral implosion protection" (thick glass on the front and metal band around the edge). I think it is just an anti-glare filter glass. OTOH American CRTs may be completely different in this aspect compared to European ones. Christian
Re: Playing with HP2640B
What did you do for the screen mold? Hot wire method to separate CRT from implosion window? Put the CRT in a hot water bath? Chip at the glue? Marc On Nov 15, 2017, at 11:48 AM, Mattis Lind via cctalkwrote: I have been working on a HP 2640B terminal. It was mostly about fixing the "screen mold" problem and cleaning up the liquids that had been seeping out from the screen down into the bottom. The small coaxial wire that connects the 4.9152 MHz clock signal form the power supply (never seen a crystal controlled SMPSU before!) to the backplane was broken off, but after fixing that the terminal worked fine. Just needed some adjustment to the brightness. With the correct terminfo installed it worked quite well as a serial terminal to a Linux box. Then I tried the short 8008 programs that Christian Corti pointed to http://computermuseum.informatik.uni-stuttgart.de/dev_en/hp2644/diag.html and ftp://computermuseum.informatik.uni-stuttgart.de/hp/hp2644 I tried both a couple of times. The terminal enter the LOADER mode but just hangs completely at the end. I tried different baudrates but no difference. The selftest STATUS line tell me 40<802 which should indicate that there are 4k memory in the terminal. However there should be 5k since there is one 4k board and one combined control store and 1 k RAM board. Maybe there is a fault in the 1k SRAM? The terminal doesn't complain though. Regardless, the programs listed either starts at adress 3 or 36000 which should then be within the available space. The question is, should these program work for the HP2640B as well? It has a 8008 but my guess is that the firmware is different from the 2644. What is the joint experience regarding this? Has anyone ran these small programs above on a HP2640B? The HP 2640B firmware consists of four EA 4900 ROM chips which annoyingly are not anything like normal EPROMs. So dumping will need special considerations. Has anyone dumped the HP 2640B firmware already? I didn't find it on bitsavers. /Mattis
Re: Playing with HP2640B
2017-11-16 1:25 GMT+01:00: > is there a dif between 40 a and 40 b with the firmware/loader/etc? > Ed# > I assume there are a difference. The document linked to below at least tell that the original A had a completely different set of ROM chips whilst rev date "April 76" only had the first ROM different. The three others were the same. http://bitsavers.trailing-edge.com/pdf/hp/terminal/HP_262x_264x_roms.pdf > > In a message dated 11/15/2017 12:48:24 P.M. US Mountain Standard Tim, > cctalk@classiccmp.org writes: > > I have been working on a HP 2640B terminal. It was mostly about fixing the > "screen mold" problem and cleaning up the liquids that had been seeping out > from the screen down into the bottom. > > The small coaxial wire that connects the 4.9152 MHz clock signal form the > power supply (never seen a crystal controlled SMPSU before!) to the > backplane was broken off, but after fixing that the terminal worked fine. > Just needed some adjustment to the brightness. > > With the correct terminfo installed it worked quite well as a serial > terminal to a Linux box. > > Then I tried the short 8008 programs that Christian Corti pointed to > > http://computermuseum.informatik.uni-stuttgart.de/dev_en/hp2644/diag.html > > and > > ftp://computermuseum.informatik.uni-stuttgart.de/hp/hp2644 > > I tried both a couple of times. The terminal enter the LOADER mode but just > hangs completely at the end. I tried different baudrates but no difference. > > The selftest STATUS line tell me 40<802 which should indicate that there > are 4k memory in the terminal. However there should be 5k since there is > one 4k board and one combined control store and 1 k RAM board. Maybe there > is a fault in the 1k SRAM? The terminal doesn't complain though. > > Regardless, the programs listed either starts at adress 3 or 36000 > which should then be within the available space. > > The question is, should these program work for the HP2640B as well? It has > a 8008 but my guess is that the firmware is different from the 2644. What > is the joint experience regarding this? Has anyone ran these small programs > above on a HP2640B? > > The HP 2640B firmware consists of four EA 4900 ROM chips which annoyingly > are not anything like normal EPROMs. So dumping will need special > considerations. > > Has anyone dumped the HP 2640B firmware already? I didn't find it on > bitsavers. > > /Mattis > >
Re: Playing with HP2640B
is there a dif between 40 a and 40 b with the firmware/loader/etc? Ed# In a message dated 11/15/2017 12:48:24 P.M. US Mountain Standard Tim, cctalk@classiccmp.org writes: I have been working on a HP 2640B terminal. It was mostly about fixing the "screen mold" problem and cleaning up the liquids that had been seeping out from the screen down into the bottom. The small coaxial wire that connects the 4.9152 MHz clock signal form the power supply (never seen a crystal controlled SMPSU before!) to the backplane was broken off, but after fixing that the terminal worked fine. Just needed some adjustment to the brightness. With the correct terminfo installed it worked quite well as a serial terminal to a Linux box. Then I tried the short 8008 programs that Christian Corti pointed to http://computermuseum.informatik.uni-stuttgart.de/dev_en/hp2644/diag.html and ftp://computermuseum.informatik.uni-stuttgart.de/hp/hp2644 I tried both a couple of times. The terminal enter the LOADER mode but just hangs completely at the end. I tried different baudrates but no difference. The selftest STATUS line tell me 40<802 which should indicate that there are 4k memory in the terminal. However there should be 5k since there is one 4k board and one combined control store and 1 k RAM board. Maybe there is a fault in the 1k SRAM? The terminal doesn't complain though. Regardless, the programs listed either starts at adress 3 or 36000 which should then be within the available space. The question is, should these program work for the HP2640B as well? It has a 8008 but my guess is that the firmware is different from the 2644. What is the joint experience regarding this? Has anyone ran these small programs above on a HP2640B? The HP 2640B firmware consists of four EA 4900 ROM chips which annoyingly are not anything like normal EPROMs. So dumping will need special considerations. Has anyone dumped the HP 2640B firmware already? I didn't find it on bitsavers. /Mattis
Playing with HP2640B
I have been working on a HP 2640B terminal. It was mostly about fixing the "screen mold" problem and cleaning up the liquids that had been seeping out from the screen down into the bottom. The small coaxial wire that connects the 4.9152 MHz clock signal form the power supply (never seen a crystal controlled SMPSU before!) to the backplane was broken off, but after fixing that the terminal worked fine. Just needed some adjustment to the brightness. With the correct terminfo installed it worked quite well as a serial terminal to a Linux box. Then I tried the short 8008 programs that Christian Corti pointed to http://computermuseum.informatik.uni-stuttgart.de/dev_en/hp2644/diag.html and ftp://computermuseum.informatik.uni-stuttgart.de/hp/hp2644 I tried both a couple of times. The terminal enter the LOADER mode but just hangs completely at the end. I tried different baudrates but no difference. The selftest STATUS line tell me 40<802 which should indicate that there are 4k memory in the terminal. However there should be 5k since there is one 4k board and one combined control store and 1 k RAM board. Maybe there is a fault in the 1k SRAM? The terminal doesn't complain though. Regardless, the programs listed either starts at adress 3 or 36000 which should then be within the available space. The question is, should these program work for the HP2640B as well? It has a 8008 but my guess is that the firmware is different from the 2644. What is the joint experience regarding this? Has anyone ran these small programs above on a HP2640B? The HP 2640B firmware consists of four EA 4900 ROM chips which annoyingly are not anything like normal EPROMs. So dumping will need special considerations. Has anyone dumped the HP 2640B firmware already? I didn't find it on bitsavers. /Mattis