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Replace your #$%& console power switch!

If “the solder joints are always bad” is rule #1 when repairing old gear, “the power switch is worn out and must be replaced” is rule #2. The TI-99/4A in-console power supply has a DPDT switch that handles +5VDC and +12VDC. The switch internals will wear grooves in the contacts over time. After nearly forty […]

Notes on reworking a low-serial-number HRD into a HRD+

Along with the Horizon 4000 (that I repaired and documented in the previous entry), IM also sent an original HRD. It uses the same board as the HRD+, but had a bit of extra glue logic and was missing the ‘259 and ‘138 stacks. It was populated with a number of stacked 6264s, and had […]