28 Jul
2025
28 Jul
'25
1:26 p.m.
Do you have a good guess of what part they used for the faster drift-field tranststors?
Not having any such in 1979 when I repaired some cards, I put in gold-doped silicon
2N4258’s and reduced the reverse bias.
Dave Wise
On Jul 28, 2025, at 7:50 AM, Jon Elson via cctalk
<cctalk(a)classiccmp.org> wrote:
On 7/27/25 17:43, Carey Schug via cctalk wrote:
maybe somebody is restoring a computer and
recognized a card they need....
LOL
SMS cards should be VERY easy to repair. The transistors are mostly 2N404
(Germanium PNP) IIRC. And, diodes are glass Germanium types. The boards are
single-sided, with no plated through holes, so the traces are a bit fragile.
Jon