hmb's latest activity

Another thing that does not look right is the amount of space between the mounting screw hole for REG1 and its three solder pads. Based...

Agree - the pad sizes could be made much smaller. They look to be twice as large as necessary. I am following the discussion with great...

Does it not seem the space between solder pads for C4 is little more than a hair's width - ie unnecessary close together?

An analysis of the voltage swing on the original Cromemco JS-1 is detailed here...

You mean like this "virtual sector generator" for 5.25" floppy drives ? https://deramp.com/vsg.html

For proper operation, the old school QumeTrak 842 does require a "TG43" input signal. In the Qume manual the "TG43" signal is actually...

While the joystick mechanism used by the Cromemco controller is mechanically similar to that found in Kraft's RC transmitters, I wonder...

86-DOS would work with a very basic serial terminal. When used with a VT-52, its function keys could be used to perform several very...

The system console was a serial terminal connected to the serial port on the SCP-300 "CPU Support Card".

The only way to find out for sure is to test it so that you can verify this claim by the manufacturer was correct. Your Delta Products...

Each of these two external drive systems required a specific H89 interface board. Needless to say these interface boards (like the Z-47...

Few H8 (or H89) systems were equipped with 8" floppy drives. The "official" Heathkit 8" drive product for the H8 was the H-47, a very...

No question - the CompuPro RAM17. It's design (like the SCP 16K board) uses the least number of parts, and S100 signals, required for an...

In Holden's discussion of the Dazzler, he mentioned having successfully tested it with the "Seattle Computer" 16K RAM board, and the...

The only board in your list that stands a chance of working with the Dazzler is the Vector Graphic 8K RAM - but I'd have to see the...