HP 3852a extended memory modules info
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Here is a collection of data I have on the Hp 3852a expansion port and memory modules :
Its a Dram module opposed to the SRAM internal memory The memory controller used is National DP8409A memory chips are Siemens 41256 There are 4 banks organized in? 9bit most likely for parity checking. The card pictured must be a 1MB version organized in 4 banks, each? bank consisting of 9 chips.? The 68000 used in the HP can address 8 bit or 16 bit words .? Since the card uses parity bits there needs to be a parity bit controller on it as well.? The 68000 processor used the Asynchronous bus control to read and write memory. User Davorin on EEVblog traced out most of the pins on the connector. HP 3852A Edge Connector ? 1????????NC 2????????NC 3????????NC 4????????NC 5????????NC 6????????NC 7????????NC 8????????NC 9????????NC 10????????NC 11????????NC 12????????NC 13????????NC 14????????NC 15????????GND 16????????GND 17????????NC 18????????NC 19????????NC 20????????NC 21????????NC 22????????NC 23????????GND 24????????GND 25????????NC 26????????NC 27????????NC 28????????NC 29????????NC 30??????????? 31????????NC 32????????NC 33????????NC 34??????????? 35????????GND 36????????GND 37????????RESET 38????????NC 39????????GND 40????????GND 41????????NC 42????????NC 43????????LDS 44????????UDS 45????????R/W 46????????AS 47????????GND 48????????GND 49????????NC 50????????A1 51????????A2 52????????A3 53????????A4 54????????A5 55????????A6 56????????A7 57????????A8 58????????A9 59????????A10 60????????A11 61????????GND 62????????GND 63????????A12 64????????A13 65????????A14 66????????A15 67????????A16 68????????A17 69????????A18 70????????A19 71????????A20 72????????A21 73????????A22 74????????A23 75????????GND 76????????U27 1820-4147 Pin 4 (74HCT573 Octal Latch?) -> D2 77????????D0 78????????D1 79????????D2 80????????D3 81????????D4 82????????D5 83????????D6 84????????D7 85????????VCC 86????????VCC 87????????D8 88????????D9 89????????D10 90????????D11 91????????D12 92????????D13 93????????D14 94????????D15 95????????NC 96????????NC 97????????NC 98????????NC 99????????NC 100????????NC ? From <> |
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I haven't looked up the pinout because I really need to get to sleep, but from the photo this board looks *exactly* like a DIO bus RAM board for an HP-9000 series 300 computer.
-Dave On May 2, 2024 8:46:01 PM "Maciej Kawalkowski, Liberty Electronics Design and Service LLC" <kawalkowski.m@...> wrote: Here is a collection of data I have on the Hp 3852a expansion port and memory modules : -- Dave McGuire, AK4HZ New Kensington, PA |
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On 5/3/24 07:20, Ed (scskits) wrote:
If the connector is still available, it would not be difficult to make a 1MB or 8MB static RAM board.Nice! If that is in fact an HP-9000 DIO RAM board, they've already been cloned. A fellow over in .eu did the design, I had a small run of PCBs done and built a few, and eventually got it working. I had intended to do a production run and sell them, but there wasn't a lot of interest on the vinthpcom list, surprisingly, so there it has sat for the past few years. -Dave -- Dave McGuire, AK4HZ New Kensington, PA |
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Ed
The connector is part of the machine and the memory card uses PCB edge as connector. There is a raiser inserted in onto the 3852A processor board like the one below. The memory card interfaces this raiser. I was thinking of making a card using? SRAM .? The 4Mbit chips? R1LP0408DSP-5SI (512kx8) would be a good choice.? 2 chips for 1MB card. Some things I am not sure of are:
Maciej |
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On 5/3/24 12:59, Maciej Kawalkowski, Liberty Electronics Design and Service LLC wrote:
HP-9000 DIO RAMThat's not the project I worked on; the one I was involved in is just pure RAM, 7.5MB to fill the address space. No ROM. There was no discrete logic; everything was implemented in a GAL, and it was all surface-mount. -Dave -- Dave McGuire, AK4HZ New Kensington, PA |
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On 5/3/24 13:11, Maciej Kawalkowski, Liberty Electronics Design and Service LLC wrote:
The Hp 9000 DIO board has the same pin out where it matters and looks like the same board type.Yes, it does look to be the same thing. I too have a 3852A by the way. It has never given me trouble, so I've never needed to open it up. -Dave -- Dave McGuire, AK4HZ New Kensington, PA |
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On 5/3/24 15:22, Maciej Kawalkowski, Liberty Electronics Design and Service LLC wrote:
I managed to find your SMD version.To be clear, I did not design that board; I fixed a few issues, readied it for production, and made a few boards. The original design was done by David Kuder. -Dave -- Dave McGuire, AK4HZ New Kensington, PA |
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He was talking to me.
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-Dave On 5/3/24 17:51, Dave Daniel wrote:
Which Dave? --
Dave McGuire, AK4HZ New Kensington, PA |
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On 5/3/24 20:05, Maciej Kawalkowski, Liberty Electronics Design and Service LLC wrote:
Moved the fuse to the topI made the same change to my version. My intention was to build a bunch of these via pick-and-place; components on the bottom with all that open space up top was...not welcome. ;) -Dave -- Dave McGuire, AK4HZ New Kensington, PA |
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On 5/3/24 19:11, Maciej Kawalkowski, Liberty Electronics Design and Service LLC wrote:
Dave McGuireThe ones that I had left are installed in HP-9000 systems at LSSM, but I could borrow one and try it. My 3852A is in a rack, though, how do you reach that board? Can I do it without taking it out of the rack? Oh yes, also...these boards are 7.5MB; didn't you mention earlier that the 3852A wouldn't address that much RAM? -Dave -- Dave McGuire, AK4HZ New Kensington, PA |
Dave McGuire