Skip to content
Skip to main navigation
Skip to first column
Skip to second column
JAQ's Blog - Electronics, Microcontrollers, DEC Minicomputers, Raspberry Pi, Airplanes and other stuff....
Total: 27 results found.
Page 1 of 2
SD-Systems SBC-200 Testing - Part 1
... interesting retro project also. Before Phillip shipped me the board we tried running a boot EPROM that, if my code was right would send a continuous stream of ‘A’ characters to the
DECUS NOPSIG Posters
... It is showing 12 windows simultaneously. This PDP-7,
No. 60, was the third DEC computer to enter Australia. It was installed at the Australian Atomic Energy Commission, Lucas Heights, ...
Northstar Horizon Repair
... Horizon with only the Z80 CPU board installed (the documentation said that the HDT ROM did not require RAM on the machine.) and a terminal connected to the left
port (commonly the console) I expected ...
GPS Connection to Hans Summers Ultimate 3 QRSS Kit
... and instead sends $GPGGA and $GPVTG at 4800 baud. The startup configuration can be changed by connecting via the
interface, changing the configuration and saving to backup memory but to retain ...
Computer Specialists Ltd - CS-16/64 Single Board Computer
... more importantly the timing clock for the SIO/0 (Z80 SIO/0
IO controller). Also a clean up around the reset circuit. Looks like a reset switch or something was removed so the board by ...
boards that live in the IO space around 7775xx. So there you go... can't trust anything with this machine. This is the second 74175 I have replaced on the M7859. Replacing ...
TRS80 Model 4 Rebuild - Part 3
With the replacement header installed on the
interface board and the modifications removed from the floppy drive controller it was time to reassemble the machine. Nothing special here but ...
SBC6120 PDP8 Replica - Part 4
... 2 pin headers and repeat the power up test. The front panel LED's will run through a memory test and eventually stop with the RUN LED not lit. If you have the
interface connected to ...
TRS80 Model 4 Rebuild - Part 2
Having sorted out the
interface connections I turned my attention to the floppy drive controller. Interestingly the machine had the spectrastrip connector between the main board and ...
TRS80 Model 4 Rebuild - Part 1
... interface board the emulates a Radio Shack hard drive. At some point in it's life this machine had lost the spectrastrip cable that connected the
interface board with the main board. As ...
Supporting Generic Kermit 4.11 in your CPM/80 BIOS
... on prototype board as long as you take your time and keep your interconnect wires short. The hardware uses a Z80-SIO to provide two
ports (with TTL to USB adaptors on my build). ...
Using eBay TTL Serial/USB Interface Modules
With most computers no longer having a
port, a TTL
/ USB interface is required for many microcontroller projects. I have had good results with the low cost eBay modules based on ...
Home Built Z80 CP/M Computer - Part 3
... The end result looks very smart. The two
interfaces use CP2102 USB/TTL
interface adaptors purchased on eBay for a couple of dollars. They work well in this application easily ...
KY11-LB Programmers Panel - Part 3
... http://www.retrocmp.com/tools/pdp-1134-programmers-console on using the KY11-LB to test other Unibus boards which I am going to try.... particularly the memory and
Home Built Z80 CP/M Computer - Part 2
... Compact Flash to IDE Adaptor on eBay (approx US$ 2). I have been testing the board with 2 x MAX3232 based TTL to RS232 converter boards. Replacing these with CP2102 based TTL to USB
CAT Interface for eBay AD9850 DDS Modules - Part 2
... following tools proved particularly useful in this process by allowing me to test the communication between HRD and my VB application without the need for
splitter cables. The Spy mode ...
PDP-11/04 - Power Supply Part 3
... powered from the 28VAC output of the main transformer. As well as 15VDC, the module also provides AC and DC Low signals and a 50hz signal for the real time clock on the DL-11W
Building a DLink DSL-502T Based IGate - TNC Schematic and Firmware
... the TNC transmitting via the
port and preventing the DSL-502T from booting. When programming an ATMega8 with the firmware ensure you set the fuses to 0xDA (High) and 0xBF (Low). Incorrect ...
Mangaging your FT-7800R memories.... with a VX5 bonus
... parts... the level conversion was easy... standard MAX232 design but additional interfacing was required to covert the two line TTL
to one line to suit the FT-7800R. I discovered this design ...
Building a DLink DSL-502T Based IGate - The TNC
In addition to configuring the DLink DSL-502T routers for the IGate project we also needed a TNC to connect between the radio and the
port. Our TNC selection was based on the following criteria: ...
PDP8 SBC6120 FP6120
My Other Sites
Contact Andrew Quinn