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TI-58C and TI-59
04-19-2019, 12:47 AM (This post was last modified: 04-19-2019 12:48 AM by Xorand.)
Post: #35
RE: TI-58C and TI-59
So I found some specs for power supplies in the TI-58/59 series.

The battery voltage is (nominally) 3.6V. There is a voltage board that also creates -10V and -16V. I found where to measure those on the TI-58 and they were -6.5V and -12.5V, respectively.

I was using my variable DC power supply to provide the 3.6V input to the calculator, so I carefully ramped up to 3.9V input. Interestingly, the two voltages remained somewhat constant if not dropping just a little. Hmm.

For reference, I pulled apart a working TI-59 that I have in the current parts pile (missing a card reader) and performed the same testing on it with about the same results. However, the display on the TI-59 was fairly brighter than the TI-58.

The TI-58 is a very early model (date stamp 4677, which is around November of 1977 - they were introduced in May of 1977). Wonder if they were just using dimmer LEDs in earlier models. My good TI-59 has the brightest display of the bunch of calculators but is a 1982 build.
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Messages In This Thread
TI-58C and TI-59 - Xorand - 03-27-2019, 08:46 PM
RE: TI-58C and TI-59 - Maximilian Hohmann - 03-28-2019, 10:09 AM
RE: TI-58C and TI-59 - Garth Wilson - 03-29-2019, 01:46 AM
RE: TI-58C and TI-59 - Maximilian Hohmann - 03-29-2019, 01:54 PM
RE: TI-58C and TI-59 - Thomas Okken - 03-29-2019, 05:50 PM
RE: TI-58C and TI-59 - Jlouis - 03-29-2019, 06:30 PM
RE: TI-58C and TI-59 - Massimo Gnerucci - 03-29-2019, 07:31 PM
RE: TI-58C and TI-59 - Garth Wilson - 04-01-2019, 02:24 AM
RE: TI-58C and TI-59 - toml_12953 - 03-31-2019, 02:13 PM
RE: TI-58C and TI-59 - Garth Wilson - 04-01-2019, 02:18 AM
RE: TI-58C and TI-59 - Dave Britten - 03-29-2019, 01:02 PM
RE: TI-58C and TI-59 - grsbanks - 03-29-2019, 06:37 PM
RE: TI-58C and TI-59 - Maximilian Hohmann - 03-29-2019, 08:27 PM
RE: TI-58C and TI-59 - Gene - 03-29-2019, 09:58 PM
RE: TI-58C and TI-59 - Maximilian Hohmann - 03-30-2019, 12:35 PM
RE: TI-58C and TI-59 - grsbanks - 03-30-2019, 12:54 PM
RE: TI-58C and TI-59 - rprosperi - 04-01-2019, 12:19 AM
RE: TI-58C and TI-59 - Gene - 04-01-2019, 01:34 AM
RE: TI-58C and TI-59 - Thomas Okken - 04-01-2019, 02:36 AM
RE: TI-58C and TI-59 - xerxes - 04-01-2019, 01:12 PM
RE: TI-58C and TI-59 - Xorand - 04-07-2019, 01:20 AM
RE: TI-58C and TI-59 - badaze - 04-01-2019, 01:08 AM
RE: TI-58C and TI-59 - Gene - 03-30-2019, 02:13 PM
RE: TI-58C and TI-59 - Maximilian Hohmann - 03-30-2019, 02:44 PM
RE: TI-58C and TI-59 - Massimo Gnerucci - 03-30-2019, 05:27 PM
RE: TI-58C and TI-59 - Xorand - 03-31-2019, 09:54 PM
RE: TI-58C and TI-59 - ijabbott - 04-18-2019, 08:59 PM
RE: TI-58C and TI-59 - Maximilian Hohmann - 04-19-2019, 08:39 AM
RE: TI-58C and TI-59 - badaze - 03-30-2019, 11:25 PM
RE: TI-58C and TI-59 - toml_12953 - 03-31-2019, 02:18 PM
RE: TI-58C and TI-59 - badaze - 03-31-2019, 07:19 PM
RE: TI-58C and TI-59 - Xorand - 04-16-2019, 01:23 AM
RE: TI-58C and TI-59 - Jlouis - 04-17-2019, 06:10 PM
RE: TI-58C and TI-59 - ijabbott - 04-17-2019, 10:56 PM
RE: TI-58C and TI-59 - Xorand - 04-18-2019, 03:54 AM
RE: TI-58C and TI-59 - Xorand - 04-19-2019 12:47 AM



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