[cctalk] Re: IBM 5100 emulation
I've poked around inside the 5100 some years ago, but most of my information came from the Maintenance Information Manual, and I only verified a little of it relating to the executable ROS. The executable ROS is split between a half card in slot H2, which is required for all 5100 models, and an APL-only executable ROS half card in slot H4. The most significant address bit (SAB 0) selects between the two. The BASIC/IO/Diagnostic executable ROS starts at address , and the APL executable ROS starts at 8000. It appears that the BASIC/IO/Diagnostic executable ROS occupies most or all of the address space allocated to it, ..7fff space (32KB). The non-executable ROS cards are: slot E2 (full size): ROS control, and common and language ROS, all models - it appears that this is addressed ABOVE (at higher addresses than) the BASIC ROS slot C4 (half card): BASIC ROS slots C2, D2, D4 (half cards): APL ROS The MIM shows the non-executable ROS as divided into banks of 30720 bytes (0x7800). I can believe that the amounts of memory on a particular card might be related to that, e.g., 15 chips of 2KB each, but the decode on the ROS Control card is shown as decoding consecutive ranges of that size, rather than e.g. units of 0x8000. Two decodes go to each non-executable ROS card, so it appears that the 0x7800 bytes of a bank are not actually implemented on a single card. Something bizarre seems to be going on, or possibly the documentation isn't 100% accurate. I think the non-executable ROS is selected slightly differently than in the 5110. The non-executable ROS is device address 1. The MIM says in one place that in a control operation, data bit 4 selects common and BASIC, while data bit 5 selects APL. Bits 4 and 5 come from bits 12 and 13 of the control microinstuction. I'm not convinced that the logic diagrams match that description.
[cctalk] Re: HP 2000 hardware in Salt Lake
I added some old videos to the Google Photos archive. Example: https://photos.app.goo.gl/2k1f9kQhbrFnU3J79 I should make some higher res versions. :) Sources here: https://rikers.org/hp2100/ Full gallery link again: https://photos.app.goo.gl/ry648oCejfmjnuNf9 On 9/19/2022 7:14 PM, Tim Riker via cctalk wrote: All, I'm not getting around to working on this hardware. Another potential move coming up. What's the interest level out there for HP 1000/2000 hardware? Computers: * HP-2116A 8kB - the original HP computer. There is only one other that I am aware of in existence. David Collins got theirs up and running. Mine still blows fuses on startup. * http://hpmuseum.net/display_item.php?hw=95 * HP-2100A - untested * HP-2108 - working last I checked 64kB (I might keep this one) * HP-2112 - working last I checked 64kB Others: * HP-7901A disc drive - untested (2.5mB) * HP-7900A disc drive - untested, with external power supply (5mB) * HP-7900A disc drive - untested, with external power supply * HP-2748B paper tape reader - spins up, does not seem to pass data * CCC tape punch - untested * HP-2761A Optical Mark Reader - punch card reader. loading wheel turned to goo long ago. probably restorable * card slot expansion chassis. I forget the part number. * dual 3 1/2" drive in hpio chassis might someday work with these systems * non-hp 19" rack holding most equipment * lot's of peripheral cards including interfaces for disc drives, punch, tape, card, etc. Photos on Google Photos. My Gallery App is down at the moment. https://photos.app.goo.gl/ry648oCejfmjnuNf9 I'd guess it's about 1500 pounds of hardware. So, pickup in Salt Lake only.
[cctalk] Re: 7485 chip history??? (Solid State Music SB-1)
Ben, I buy lots of stuff from eBay US sellers and most are willing to check/fix shipping costs. If not then I use a drop-box service where the item is shipped to Oregon, and then reshipped to me for a not too horrible cost. Lastly, I’ll be back at my shop in Burnaby in a couple of days and can check my inventory of TTL chips - might well have your 74L85, and postage is pretty cheap within Canada. I’ll try not to hose you too badly on the chip cost! John :-#)# > On Sep 20, 2022, at 5:52 AM, ben via cctalk wrote: > > On 2022-09-19 10:18 p.m., Tom Hunter via cctalk wrote: >> There are a few US based Ebay sellers of the 74L85. >> Tom > But most ebay sellers, from the USA seem to sell a item for $6.00 and > $75 shipping to Canada. China $2 and $3 shipping. With Covid all shipping is > several weeks. > Ben. > > >
