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JAQ's Blog - Electronics, Microcontrollers, DEC Minicomputers, Raspberry Pi, Airplanes and other stuff....
Total: 14 results found.
TRS-80 Model 1 FreHD Expansion Interface
Fred Vecoven's FreHD Hard Disk emulator has been a very popular upgrade for TRS-80 Model 3 and 4 users since its launch in 2014. If you have a Model 1 with a Radio Shack expansion interface ...
TRS80 Model 4P FreHD Installation
Following on from the post about the Model 4 FreHD installation, here are a few pictures showing the installation of a FreHD Hard Disk Emulator in my TRS-80 Model 4P. The mounting chassis is the ...
TRS80 Model 4 Internal FreHD Install
A few pictures showing the installation of a FreHD Hard Disk Emulator in one of my TRS-80 Model 4's. The mounting chassis is the frame from a dead Seagate ST4766N hard drive. I picked ...
Kaypro / FreHD Adaptor
... a Kaypro? The FreHD interface connector is, with the exception of /EXTIOSEL standard Z80 address, data and IO control signals with the same pinout as the
Model 3 and 4 expansion connector. Connecting ...
TRS80 Model 1 Fixup - Part 3
So with a power supply, working power switch, restored Expansion Interface and a suitable case, things were looking good for a quick test of the Model 1 / FreHD adaptor and move on to the next project. ...
TRS80 Model 1 Fixup - Part 2
Included in Ian's box of "things from the junk box" for FreHD testing was a Model 1 Expansion Interface PCB. Ian tells me that a common problem is people shipping Expansion Interfaces with ...
TRS80 Model 1 Fixup - Part 1
... supply design by Dean Bear that is documented on
.com. There is a good writeup on this design in the September 2013 issue of TRS8BIT available at trs-80.org.uk For my test ...
TRS80 Model 4 128K Upgrade - Part 2
The Samsung KM4164B-12 parts arrived from Bulgaria promptly and well packaged. After installing in the Model 4, the machine was left running the Model 4 diagnostics memory test for 4 hours ...
TRS80 Model 4 128K Upgrade
The TRS-80 Model 4 is regarded by many as one of the pinacles of Z80 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 Rebuild - Part 4
Model 4 works well with the two internal 3.5" drives. The challenge is sharing files with the other two stock machines which have 5.25" single sided floppy drives. In the ...
TRS80 Model 4 Rebuild - Part 3
With the replacement header installed on the serial interface board and the modifications removed from the floppy drive controller it was time to reassemble the machine. Nothing special here but ...
TRS80 Model 4 Rebuild - Part 2
Having sorted out the serial 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
While my Model 3 and one Model 4 are stock configuration machines, the one with the failed CPU from the previous post is definitely not. I got it through the New Zealand Trade and Exchange newspaper ...
TRS80 Model 4 Fault
Model 4 had been languishing in the workshop for a few years and was finally due some attention. Inspired by Ian Mavric's "Building the Super Micro" article I did a complete disassembly, ...
PDP8 SBC6120 FP6120
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