4116 ram tester

This is 4116 dram tester. I order clear pcb rev2 and assemble. Now works fine. Actually it need for repair atari 65xe with damaged ram. Now I can repair my atari! ;) gerber available on my site, as well as bom list Schematic also can help while assembling. ps. several mods available from Alex Wierzbowsky [RBSC] on his github Photos up

December 6, 2024

Apple 2 saturn128 memory card

Saturn 128 memory expansion card. 128k ram for Apple II. New (small) version. Links Forum with author post about this card. Firmware for GAL20V8B Another one implementation saturn 128 compatible card Original manual of saturn 128 card Photos my card

November 3, 2024

Apple 2 SD floppy

DISK II emulator for APPLE II from Nishido. He is close site with english translation because many people copy gerber and schematic and sell this board. But japanise version still available. Connector description top with marker here 1 3 5 7 09 11 13 15 17 19 2 4 6 8 10 12 14 16 18 20 1:GND 2:STEP0 4:STEP1 6:STEP2 8:STEP3 10:WRITE REQUEST' 12:+5V 14:DRIVE ENABLE' 16:READ PULSE 18:WRITE SIGNAL...

November 3, 2024

Kello clock v4

Clock are my weekness… ;) This is pretty one clock. A bit bigger, but very functional. I order clear PCB and now start soldering… Links Original author site about this clock here Photo Photos of process will be added. step 1 (up) step 1 (down)

November 2, 2024

Chineese led clock

Clock are my weekness… ;) Some time ago I found funny clock on aliexpress. Try deal, I think and order this one. It was compelete kit, so easy to assemble. I gave a task to my old son to solder it. One hour later task was done. Really good work. Btw, the clock is running accurately. No difference in a week. Links I re-create schematic for this clock and publish on my github...

October 25, 2024

Oric ATMOS 1 (clone)

Clone of original ORIC ATMOS 1983. Very interested computer from past. Works on 6502, has 48k memory. Actually it was not very success computer, but … this is a reason to build this one. I order clear PCB and start building by myself. Board has errors. Another part of R26 should be connected to ground (nearest C10) (picture 1). Pin1 of IC20 not connected. Should be connected to nearest via hole (picture 2)....

September 2, 2024

CF 8bit card

Overview Cheap and clean ISA 8bit card for cf cards. I order clean pcb. Links bom list to assemble board gerber archive to reproduce pcb firmware 6.14 for 1mbit rom firmware 6.22 for 1mbit rom Photo clear pcb

July 30, 2024

Ausha CP/M computer

Overview I want to have some old computer with CP/M. I seen different variants, but somehow I found on the forum PCB named AUSHA. I order PCB and start assembling. This is single board computer with soviet union chips, easy to build. It has Z80 CPU, 64kb ram, 64kb rom, Serial and IDE connector, I/O ports. Author site about this computer here Schematic in gif BOM list in xls Keyboard connector pinout...

July 3, 2024

Commodore64 sd2iec

Overview Commodore64 adapter from dataset to sd card. I order clean pcb Links EasyEDA with this board bom list with componets schematic this board firmware for atmega Photo clear pcb top clear pcb bottom

June 18, 2024

Simm 4mb with parity

Overview Selfmade cimm 4mb for old computers Photo clear pcb assembled

June 18, 2024