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JAQ's Blog - Electronics, Microcontrollers, DEC Minicomputers, Raspberry Pi, Airplanes and other stuff....
Total: 18 results found.
SD-Systems SBC-200 Testing - Part 1
... was having getting the board to reset using the motherboard reset button and had to use creative techniques like grounding the
/RESET pin with a piece of wire. Interesting! The documentation ...
Replacing 2708 EPROM with 28C16 EEPROM
... is a very good chance that neither will write (or even read) older parts even if the "supported parts list" suggests they will. I ran into this problem with the 2708 EPROM on the Northstar ZPB
Northstar Horizon Repair
... machine. It is in stock Horizon configuration with a ZPB
CPU board, HRAM-64 Dynamic Memory board and MDS Floppy Disk Controller board. It came with a large pile of manuals with "Anderson Digital ...
TRS-80 Model 1 FreHD Expansion Interface
... who want to put something into this address block... such as the
Monitor from the Dick Smith System/80 Blue Label) and a PIC microcontroller. The PIC emulates just enough of a WD1771 ...
Computer Specialists Ltd - CS-16/64 Single Board Computer
A while back I was given a
single board computer by Keith (ZL1BQE) when he found out that I really liked the
microprocessor. The board was made in New Zealand by Computer Specialists Ltd ...
Kaypro / FreHD Adaptor - Part 3
... I used the same machine SIL strips that I use as sockets for the ROM and
. Inserting these between the SHIM and the PCB sockets worked. The higher socketed chips were well cleared and the ...
Kaypro / FreHD Adaptor - Part 2
... pin header problem was solved using headers from eBay and offsetting the header that connects to the Kaypro PCB socket from the sockets on the shim where the
and 28C256 EEPROM are installed. ...
Kaypro / FreHD Adaptor
... a WD1010 Hard Disk controller + Hard Disk combination. Western Digital Hard Disk controllers were fairly common in the early 80's with many available as after market additions for the
+ CP/M ...
System 80 / FreHD Adaptor
... Model 1 which combined the
/WR, /RD and /IORQ signals to generate /IN and /OUT (and needed to be seperated back to the standard signals by the 26-1132), the System 80 provides the standard signals ...
TRS80 Model 4 128K Upgrade
The TRS-80 Model 4 is regarded by many as one of the pinacles of
development and as a lucky owner of several of these machines I do what I can to keep them operating, to supplement their capabilities ...
TRS80 Model 4 Fault
... the power on pins 11 (VCC) and 29 (VSS) of the
(U57). This read 4.7 volts... a little lower than I expected but was consistent if I powered the main board from either power supply so I assumed ...
SBC6120 PDP8 Replica - Part 1
... looking machine with the blinking lights and front panel switches. I wonder what happened to it? Fast forward to 2012 and having completed the
machine on prototype board I was ...
Supporting Generic Kermit 4.11 in your CPM/80 BIOS
I have written about my home built
CP/M computer in earlier posts. Based on a design by Grant Searle (http://searle.hostei.com/grant/cpm/index.html) this fabulous litle machine is easily built ...
Using eBay TTL Serial/USB Interface Modules
... hardware handshake lines such as RTS and CTS. The
single board computer requires RTS handshaking and the initial modules I ordered did not support this. If you need hardware handshaking ...
Home Built Z80 CP/M Computer - Part 3
Single Board Computer is mostly (still needs front panel LED's for power and HDD access) complete and mounted in a Jaycar instrument case. An interesting exercise was creating the ...
Home Built Z80 CP/M Computer - Part 2
Boots CP/M 2.2 off the compact flash card.... 8 x 8mb drives (luxury in 1980). Rather than wire directly to the Compact Flash connector like Grant did on this prototype, I ordered a low cost ...
Home Built Z80 CP/M Computer
... size... I built up the
machine described on http://searle.hostei.com/grant/cpm/index.html using parts recycled from some old telephone testing equipment. ...
Building simh for OpenWRT
... $/altair_sio.c $/altair_cpu.c $/altair_dsk.c \ $/altair_sys.c ALTAIR_OPT = -I $ ALTAIR
D = Altair
_cpu_nommu.c \ $/altair
PDP8 SBC6120 FP6120
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