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Someone who damaged a capacitor near the power connector on the mainboard of their VaxStation 3100, asked me for a photo. Unfortunately, my photos do not reveal any text. I wonder if someone knows where to find the main board schematics for the 3100? I have included a photo of the damaged...

I am selling this DECVaxstation: DEC VAXSTATION 3100-38 VS42A-CC KA42-A 24MB RAM RZ24 204MB SCSI HDD 8 PLANE GFX graphics I have too many projects, so I wanted a DEC computer that would work. I bought this VaxStation in November 2022 on e-b-a-y, and the seller told me that it was refurbished...

Hi, sorry if that question looks strange. There was a PDP-11 trainer, one SBC (Falcon), and several modern SBC projects around J11 and F11, I was wondering if the same thing happened for the VAX architecture? Thanks! Jean-Pierre

Beware this is a weird idea! I know that some Sun stations used two 68000 CPUs to implement virtual memory (one in advance of one instruction wrt the other). There is also a smart contraption named KimKlone which adds registers to a regular 6502. Are there other examples using microprocessors to...

Hi, when I changed of job in the 1990' I kept a 68K VME board that must have been used to drive a bank of V23 modems. If I remember correctly they were used to communicate with Minitels, the French videotext. At that time I intended to use it to build later a computer with it. I had in that job...

Hi all, My station shows a new error message at startup. What do you think about it? Thanks for any comment! Jean-Pierre

Hi, I have a good photo of a PCB, I would like to create a PCB from it, to be able to send it to online PCB makers. As it is a high-resolution color photo, when I convert it to black and white, there are a lot of smears because of the gradients of colors and variations of lightning. I tried...

Hi if someone is interested in building a CPU with 8 am2901 and 2 am2910, I have that in my garage in Brittany/France. => I do not know if they are still in a working state <= Please note 6 of them are am2901cpc so they are one of the fastest in the family. And two are am2901bdc...

Hi all, I guess any Floppy/CDROM on a VaxStation 3100 model 38 would have to use Centronics CN-50 SCSI interface? On ebay a SCSI floppy drive costs more than my VaxStation, is there some means to use a PC floppy disk (Shugart Associates SA400 FDD interface) through some SCSI CN-50 => Shugart...

I understand that PDP-11 has a 16 bits address bus, while there are multiple versions of QBUS and memory boards (16/18/22bits). I know there are many ways to extend an address bus with a MMU, the most common and simple MMU is probably 74ALS610. Please, can you explain to me how this address...

Hello, There are excellent replicas of KIM-1 such as this one and amateurs are discussing such reproductions in forums like that forum. There are 6502->65816 schematics (Daryl Rictor, Ruud Baltissen). I am correct to think a Kicad schematics like the one from Eduardo Casino and adaptor...

Hi all, I would like to find a DEC case/chassis/enclosure/mounting box, that would accept a 4X4 QBUS backplane. A plus would be if it had a working power supply and front panel. Ideally, it would be in Euro zone in order to minimize shipping costs and customs fees. Thanks! Jean-Pierre

Hello, Sorry if this is the wrong forum. I looked at MOS-32M which is a Russian clone of DEC's MicroVMS 4.5 operating system on this website: http://mirrors.pdp-11.ru/_vax/_MOC-32/MOC-32M45/ Ideally, I would have been interested in finding MOS-32M sources, as it is supposed to be a clone (as...

HI all, I had a SYM-1 in the old times, but I gave it to a friend for who I have written a system to compose music (on a French Minitel) and play that music simultaneously on four analog MooG synthesizers (a real time kernel). The SYM-1 had also a 16 Kbytes dynamic RAM designed and wrapped by...

Hello, Someone wants to sell me a microPDP-11 but there is no marking such as 11/53/11/73. Could it be one of the first microPDP-11 with a LSI-11/KDF11 CPU ? Thanks! Jean-Pierre

Dear all, I never used Kicad or any other PCB design tool before today, so I am sorry for the dumb things I will write in this post. My goal would be to make a poor man QBus backplane with Aliexpress connectors (for the cost in EU) and a PCB backplane. At first I thought that I could modify the...

Hi all, I am considering building my own QBus Q/Q with wire-wrap for LSI-11 cards, because finding an existing one is difficult and costly. For connectors it looks to me that Vector R600 edge connectors or similar fit the cards' connectors. I read too quickly the chapter 6 of the LSI-11 bus...

Hello, Could it be possible to access to ODT from a M7264 LSI-11 CPU (first generation, not -BB, -YA, etc) when it is used with a DLV11 (M7940 or M8017 or M8028 or compatible hardware). Thanks! Jean-Pierre

I wish everybody a happy new year! I have a VaxStation 3100, and managed to make it boot. Unfortunately I have no adapter for the video port so I am using the console port. I connected a MMJ connector to a USB cable after some trials and errors. It is used with a Linux computer and Minicom. But...

Hi all, On a French ad site there is this ad of (sic) IBM PDP11 computers. https://www.leboncoin.fr/informatique/2104377498.htm What are those computers? The seller tells: "Sell lot of old IBM PDP11. Some for parts and some in working order. Contact me if interested to make an offer." I didn't...