On 03/07/2025 4:04 PM EST Wayne S via cctalk &lt;cctalk(a)classiccmp.org&gt; wrote: Try here. Might have to create an account. <https://www.jotrin.com/product/parts/49C402BG84> IDT - 49C402BG84<https://www.jotrin.com/product/parts/49C402BG84> jotrin.com<https://www.jotrin.com/product/parts/49C402BG84> [favicon.ico]<https://www.jotrin.com/product/parts/49C402BG84> Sent from my iPhone On Mar 7, 2025, at 12:42, Holm Tiffe via cctalk &lt;cctalk(a)classiccmp.org&gt; wrote: Hi all, I'm dreaming to build sometimes my own Bit Slice CPU (when I have spare time) and I have collected several IC's in the last years for this purpose. Today a small antistatic bag with 4x IDT49C402BG84 and two IDT 49C410J fell in my hands while I was sorting some stuff. I know what they are and what they could do, they are able to help me to build a Bit Slice CPU w/o very large PCB's connecting hordes of 2901 etc. Besides of that they are CMOS and should draw much less power. But I have a problem with the 49C402: All datasheets that I could find until now, don't have the pinput auf that nice PGA84 package, there are DIP68, LCC/PLCC68 G68 or PG68 and QE68 "Cerquad" pinouts listet in every datasheet, but I have 4 chips in a PGA84 housing... This ebay page has pictures: https://www.ebay.com/p/10020043211 I don't have anything todo with the seller. Can anyone help finding the pinout? The chips itself don't seem to that seldom... Kind Regards, Holm -- Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583 info(a)tsht.de Tel +49 37292 709778 Mobil: 0172 8790 741

The HP Portable Plus computer ROM Drawer uses 28 pin 1MBit (128K) Mask ROMs (TC531000) or 512KBit EPROMs (27C512). A few years ago a company called Personalized Software made something called a ROMBO.  This was an adapter that allowed the use of a 32 Pin 27C010 Quad Pack and plugged into the 28 pin socket on the ROM Drawer. The down side of this was that the ROMBO needed a special EPROM programmer to program.  Here is a link to a picture of the ROMBO.  These are no longer available. https://drive.google.com/file/d/1VKaWpfTIgDriStECXqfptBjHoL6wEmN6/view?usp=… I am thinking of doing something like the schematic linked below to use a modern flash chip (AT28C010) in place of the 27010 and bring out the three pins necessary for programming to jumpers that can be connected to a flash programmer (or I might make an adapter board that the board plugs into for programming). https://drive.google.com/file/d/18RsZPBJldTyxzjozVlO9okfpgOK7P2QT/view?usp=… Has anyone made anything like this for the portable plus or seen something similar. I also have the following questions: 1.  Is there enough room in the ROM Drawer for some kind of socket on the adapter board? 2.  Where can I find the low profile pins used in the ROMBO? 3.  Have I missed anything? Thank you...

Digikey has the part listed ($166 each) and their page has a link to the datasheet that seems to have the pga package: Digikey https://www.digikey.com/en/products/detail/rochester-electronics-llc/49C402… Direct to Datasheet https://rocelec.widen.net/view/pdf/rbdjetrmoo/IDTIS12976-1.pdf?t.download=t… Will

You just can't beat the person who never gives up. Babe Ruth

On Sun, Mar 9, 2025 at 1:27 AM Holm Tiffe via cctalk &lt;cctalk(a)classiccmp.org&gt; wrote: See also Section 11.1, Page 4 (Page 685 of the PDF) http://www.bitsavers.org/components/idt/_dataBooks/1995_IDT_High-Performanc…

On 2025-03-07 1:36 p.m., Holm Tiffe via cctalk wrote: You really want N3002N 2 bit, bit slices, 9 for 18 BITS, 10 for 20 BITS.

if you must go to the dark side, 16 or 32 bit design pick up a 16 bit alu in a PLCC 68 package. I have been doing a lot of work with CPLD's ATF1508 and (the chips are easy to program) are easy remove/insert into the sockets. https://store.rosco-m68k.com/products/little-atf-programmer

I had some 16 bit slices, but had problems with the 64 pin dip package for a 20 bit cpu. I later tried a regular 2901's. I also needed to use 22v10's all over the place. The biggest problem was design had bus timing issues, it worked for few minutes and then quit.

Poland seems to have alot of odd stuff on ebay like N3002's. Hint, Hint :)

While waiting for data, now is good time to think about software. Ben.

PS. I have older pcbs mostly working, of a 18 bit cpu ready to go to a good home. PPS. Still writing software, so the hardware is not ready to ship. You do want a working bootstrap program!

On 2025-03-09 3:24 a.m., Holm Tiffe via cctalk wrote: Real hardware, needs a working front panel, and memory.

Real software gets toggled in.

Did the bootstrap loader that way into eeprom, once. Later I found space in a CPLD that I put the boot loader in.

The real computer is it when halts with 3 in the AC, after adding 1 + 2. if you get 5, you are using large values of 2.

if you get 42, you have mice problems. :)

It takes a lot of work to get here on any cpu. Ben.

On 2025-03-09 12:35 p.m., Holm Tiffe via cctalk wrote: Reads the paper. Taped to the wall is a line-printer Snoopy calendar for the year 1969. Looks Arg !!! Mine is Spock from 1973. http://www.users.on.net/~farnik/wikicgi/wiki.pl?SnoopyCalendar

You find your own stash! You are not getting mine. I just love them, but mine are defective they just display in octal :)

Trade you my extra spare time, for some 'round to-its'.

On 2025-03-08 8:09 a.m., emanuel stiebler via cctalk wrote: Well it so quiet, I never heard about it. Where is it? Ben.

On 3/9/25 04:14, Holm Tiffe via cctalk wrote: In about 1982 I built a 32-bit bit slice machine using 8 X 2903 and a 2910 sequencer.  I had it set up with 1K of 96-bit wide control store, and it ran 2-address operations at 8 MHz and 3-address at 6 MHz.  See : http://pico-systems.com/stories/1982.html  for some text and photos.

Unfortunately, I badly underestimated the effort to get a complete system based on this working and abandoned the project. I did have a console program that ran on CP/M that could load microcode, load and examine registers, and start the micromachine.  I then had to build a memory interface and system bus controller, and add a few small details for instruction dispatch and instruction fetching optimization.  THEN** I had to figure out some way to get a Pascal compiler for the 360 architecture and create an OS and utilities.  A big job! Jon

The 2903 was a VERY nice bit slice chip, it could do single-cycle multiply and divide, as it had an extra shift register for the multiplier bits.

  The 29203 is pin compatible, but faster.  Once I got the whole system running, I planned to upgrade to the 29203. I had planned to make device controllers with 4 74S181s and a dual-port ram chip for registers, and the control store would be 27C32 EPROMs of the fastest grade.  I was hoping to get 4 MIPS from these.

Of course, now this could all be built on a few FPGAs, and get vastly higher performance.

Yes, a small peripheral controller would be a much more practical project. Jon

On 2025-03-13 10:47 a.m., Holm Tiffe via cctalk wrote: Most designs seem to 8 bitter's, and all memory fits in block ram. Once you hit external ram/rom things slow down again.  ADHL is a nice way to program CPLD's and FPGA's.  I tried using Altera fpga's, but routing never worked reliable for me.  Since every brand of FPGA is just a little different, I never could port stuff using Verlog or VHDL. WinCUPL is what I use to program CPLD's (Amtel) now.

For building stuff, your choice of crystal oscillators is really limited so you are stuck with common speeds. Making it fast might not be possible if your timing is off by a few nS and you have to pick the next slower sized oscillator.

Jon Elson via cctalk wrote: [..] WS59032 multiply ...and you can expand the Registers externally with AM29705 (AM29707) running, I store from The 49C402 has an expanded Register set (64 words instead of 16), an double set of ALU Commands. Don't know if it is the same as on the 2903/203. It contains the carry readahed circuity too and is 60% faster IDT says... The 27C32 would be the bottleneck. I've bought some used AM27C291 in the past (and compatible Parts from Cypress and TI). I've pesteres the german company Conitec to implement device support for those for ther GALEP Devices. Send 10 chips to them and got a Mail later that they would need more..they where noe all defective now... The Read Support was added for the GALEP III and IV ..but I'm would'nt pay additionally and finally build a prommer fort those differential Eproms myself. I'ts working and no Chip hat to die for it... But even with those Eproms (25..55ns) it would be impractical to build an control store for a single experimental device out of it. I've build an control store out of old cache RAMs (8kx8). (A friend of mine collected many of them for me..out of old 486 Mainboards) An Atmega16 with an 4Mbit Atmel Dataflash could store the Microcode and load it in the WCS. There are still some Pipeline Registers to solder in and finally to write the Software for the AVR. ..it's laying around for years now. :-| This all was before I knew about IDT71502 WCS Chips that include serial shift registers.. We had an Company here in Germany that sold used chips from recycled pcbs one..the new management endet this. But before it ended I've bought a bunch of them, besides things like J11, Bus drivers AM29828 and much other things for a very small amount of bucks. (From the point I've told them that I wanted the chips to build something out of it and I'm not interrested to only look at nice gold ceramic Chips w/o any scratches..it seems that they send me the best looking Ic's they had.. :-) ) higher That's the point where the fun ends..at least for me. Yes, I've done some designs on Altera CPLDs (schematic entry only), bought a book about Verilog and one about VHDL .. but spare time is low... I don't even want to build a "fast" computer ...nice if it's fast, but it isn't necessary. I'm sitting on a PC with an Ryzen 5-3600 and 64Gbyte RAM (no, no Flash disk, but a RAID arry of fast SAS "spinning rust" disks..) project. Exactly. First is to get something running.. In the old AM29xx Docs (Donnamaye E. White) are even "controllers" described that don't use any ALU at all, but an AM2910 only. As long you don't have to shuffle some data, this will be sufficient.. (Coffee machine?) Regards, Holm -- Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, Goethestrasse 15, 09569 Oederan, USt-Id: DE253710583 info(a)tsht.de Tel +49 37292 709778 Mobil: 0172 8790 741

On Thu, Mar 13, 2025, 12:37 PM Mike Stein via cctalk < cctalk(a)classiccmp.org&gt; wrote: How big and how fast? Cypress made some 15ns UV eraseable parts, for example CY7C245A-15WC http://www.bitsavers.org/components/cypress/_dataBooks/1995_Cypress_High-Pe… Chapter 4 I have some CY7C291A-35WC parts I bought to upgrade the microcode of an HP 1000 A900 12201-60001 Sequencer Card. (Haven't gotten around to doing that yet).

On 3/13/25 11:47, Holm Tiffe via cctalk wrote: Actually, the 2903 didn't have any general registers at all. And, yes the 29705 provided dual-port registers for the 2903, that's what I used in my bit-slice CPU project. Jon

Wow!  You leave a project abandoned for 40 years (yes, it has REALLY been that long!!) and you think you still know stuff!  But, it all fades!

I totally forgot about the on-chip register file!  Thanks for correcting me.

Jon

On 3/13/25 18:17, Holm Tiffe via cctalk wrote: Wow!  You leave a project abandoned for 40 years (yes, it has REALLY been that long!!) and you think you still know stuff!  But, it all fades! I totally forgot about the on-chip register file!  Thanks for correcting me. Jon

I don't think it fades, just slower access time.

One FPGA will easily do a VLIW sequencer + scalar mills (one or more, memory / MAC assemblies) or a simple processor

Something like https://www.aliexpress.com/item/1005005779045608.html provides a wholly adequate platform for a microcoded processor, with lots of 3v3 IO for external logic analysis inputs

Martin

Depends on which one. RTL was 3.6 volts positive, as far as I can remember. I actually have a keyboard that has some of those devices in it. Yes, ECL is around 3 volts also but negative supply. And of course some people designed systems with positive supplies but "negative" logic, in the sense that ~0 volts is logic 1 while near-VCC is logic 0; the CDC 6000 series machines are an example.

FPGAs come in amazing sizes if you have sufficient money. I hope some day to cram an entire CDC 6600 into an FPGA. The main problem with this isn't FPGA sizes (by today's standards, an upper-midrange FPGA can do the job, memory included) but rather the creation of an accurate model given the bizarre and hairy timing of that machine. I have a gate level model, but it doesn't work yet because of those issues.

paul

On Mar 13, 2025, at 7:56 PM, Paul Koning via cctalk &lt;cctalk(a)classiccmp.org&gt; wrote: To understand fully how the 6000 machines work, ...

On Mar 13, 2025, at 7:56 PM, Paul Koning via cctalk &lt;cctalk(a)classiccmp.org&gt; wrote: To understand fully how the 6000 machines work, ...

it. Yes, ECL is around 3 volts also but negative supply. And of course

I can think of several places where DEC used 2901 designs. One is the VAX 730. One of the PostScript laser printers also used these, I think -- LPS20 perhaps? Not the LPS40, that was a microVAX running VaxELAN based firmware.

Another, and an interesting one, is the UDA50. It has a 16 bit engine using 4 2901s plus a 2910 sequencer. My mentor Anton Chernoff worked on the microcode for it and showed me some of it. I remember it had a specialized assembler where the ALU opcode (for the 2901) was in the left half of the line, and the sequencer opcode (for the 2910) in the right half, separated by a semicolon. The 2901 had condition codes, which were transferred to the 2910 for conditional branches, but with a one cycle delay at least in the UDA50. So you could see weird stuff like this: clr r1 ; bne foo because the conditional branch would act on the condition codes set by the preceding line's ALU part. The UDA50 had an implementation, in a tiny amount of microcode, for a small 16-bit microprocessor instruction set. I think it was roughly a very much simplified PDP-11. That was used for various downloadable diagnostics and service tools, like a disk formatter. Richie Lary of PDP-8 fame wrote that part of the microcode. paul