Thanks Jos, I hadn't realized how similar the DP1100 is. This brochure has a great image of the font right on the front page (80x12 text): http://www.bitsavers.org/pdf/datapoint/1100/Dataform_1100_Brochure_1974.pdf
And it's probably a safe bet that it's the same font as in the 1972 models. Would be neat to see the entire character set. In the photo, the screen looks fairly inset -- like maybe an inch? That's good for keeping glare off the screen. I see there was a Cassette 1100 and Disk 1100 (by '75): http://www.bitsavers.org/pdf/datapoint/1100/60259_1100_Brochure_1975.pdf Then I came across a DP2200 emulator, except -- it was apparently made in 1973 and ran on a DP2200! (ACM link, but click the PDF, it's freely available) https://dl.acm.org/doi/10.1145/800192.805722 What a neat system. In an old IBM 5110, I replaced its power supply with modern components. From the DP2200 manual, it looks like it needs -5 -12 +5 +12 and +24V? There is a "trick" in the modern buck-boost voltage converters to get negative voltage (the IBM PSU needs -5 -12 +5 +12 and +8.5V). I put notes about it here: https://voidstar.blog/ibm-5100-power-supply/ Maybe something similar can be done for the old DP's? I understand for authentic/historical perspective all original components is prefered, but using a substitute PSU is reasonable for checking out the rest of the system. Were there any contemporary complaints about the DP PSU in the mid-1970s? Like was it noisy, ran hot, cause any fires? I recall a talk from one of the early 1980s Commodore engineer, where he was amazed ANY C64 was still running since the components were truly not designed to last more than a few years. What an amazing system those Datapoints were, for their time. The chicken-farm story in the DP2200 book is really fun - these farmers being savvy enough to code up what they needed, and the systems compact enough to fit in the farms and using modems even to sync up data (pre-1975). The IBM 5100: 64x16 screen (instead of 80x12 used in DP), and a slightly larger "box"(case) that had a "horn" inside for better airflow over all the components (not an audible horn, but a thing that channel air from the PSU fan to distribute over all the electronic cards and display circuits). Plus the 5100 supported the external BNC video (I'm not sure if any of the DP systems had an external video connector? I didn't see it mentioned in the DP2200 manual) - I've put 3x extra CRT's chained up to the IBM 5100, in the manual I think it says it can go up to 16 (not sure what the limiting factor of that signal is). I'm not sure if quality-wise the IBM PSU was "better" (it takes about 3/4th of the back half of the case, the other 1/4th for the fan) - other than to say quite a few 5100's are still running in the world. Maybe all that altogether makes it (the 5100) a more "portable" system (construction sites, forward edge battlespace, etc -- i.e. being more robust to handle outside heat). Also it had a minimum of 8K. The APL stuff made the 5100 expensive, but the base BASIC model was ~$9K (I think even with the single QIC tape for 207KB storage; but that price didn't include async/comm cards). Weren't base DPs $5K-$7K (all throughout 72-75) ? But, in extracting the data on those TTLs, it seems like a modern replica of a DP2200 would be possible. Can't say the same for the 5100 because apparently nobody left on the planet understands those MOSFET silver cans (and how to extract the 6KB of content from them). Sorry for the tangent:) I really was just curious about the DP2200 font, and possibly seeing where it came from (just based on its style). The DP has a better "0" (zero) font than the 5100 :) (IMO) -Steve On Sun, Nov 13, 2022 at 3:45 AM jos via cctalk <cctalk@classiccmp.org> wrote: > On 13.11.22 07:13, Steve Lewis via cctalk wrote: > > I've been looking for a video or image that shows what font the original > > Datapoint 2200 used. > > > > It's not shown in the manual. There is one vintage image with the > office > > lady and the DP2200 on the desk- but the font isn't very clear in that. > > > > In any modern video about the DP2200, none of them seem to power it on -- > > which is certainly understandable. From what I've read, the power > supply > > of that system is prone to failure. Also, the system is hard-coded to > load > > from Tape 1 -- which means both the tape drive, and tape media, still > needs > > to be in good working order (which would be pretty rare after this time). > > > > In "the" DP2200 book, it only briefly mentions that the original tape > > software was developed "on an HP system" (without any elaboration that I > > could tell on which HP system that was). > > > > Nothing in the manual suggests the original DP2200 could "program itself" > > (i.e. no built in machine code monitor -- those TTL chips had one strict > > boot up sequence: load from tape 1). If there was a read error or no > tape > > available, I'm curious if any message showed on the CRT. > > > > So, I was just wondering if there was any known pre-1973 Datapoint 2200's > > that are still working? (and/or if any HD video of them powered on and > > legible font can be seen) Or any other more current system that we know > > for sure used the same font? > > > > Thanks! > > -Steve > > > Not only is the powersupply prone to failure, it is also the most > dangerous I have ever seen, and I am hesitant on working it. Primary and > secondary sides not separated, isolation between the two almost > nonexistant, many primary nodes exposed. Would never pass modern safety > checks. > > But here is a picture of my DP1100, a DP2200 derivative, while it was > running a memory selftest, for a short time in 2021, before the powersupply > blew again : > > > https://forum.vcfed.org/index.php?threads/its-alive-my-datapoint-2200-1100.1222197/#post-1222197 > > While the DP2200 is hardcoded to start from tape, the DP1100, otherwise > identical, boots from a ROM. This ROM also contains a minimal machinecode > monitor. I recovered & disasembled the ROM and Gordon Peterson, from > Datapoint, commented it out : > http://www.bitsavers.org/pdf/datapoint/1100/DisketteBootDisassemblyGEP2.txt > > Note that there are multiple videoboard options : the later DP2200, my > DP1100, and the DP5500 share the same videoboard. This relies on a > programmable characterset. In the disassembly mentioned above above, > starting at line 3660 you will see a load of gobldecook, these are actually > fondsets to be loaded into the machine. > > The fontset has a very particular "look" to it. How much is due to > fontdefinition, and how much is due to the diddlescan, that I dont know. > Diddlescan is where they scan each character in full, before proceding to > the next. > > Note that a ROM based bootboard for a DP2200 would be a trivial > undertaking, and only involve changing the cassette reader board for the > ROM board. > > > Jos > > >
