daver2's latest activity

Can you get at the bridge rectifiers? If so, I suspect you can reform the majority of these capacitors without removing them if that is...

>>> You could always check the CPU is being reset, but even if it wasn't, there should still be H & V drive pulses sent to the VDU. The...

My personal view is to get it working for posterity - providing it is 'sympathetic' to the era. The original builder/owner would (I am...

>>> See the above comment - only this machine exhibits this behavior, even after I swap between keyboards, which I think indicates the...

You can also check the key matrix with a multimeter. The most likely cause of your issue is a shorted switch contact - so you are going...

Well, not the true datasheet for the 240RB4 - but the manual for rejuvenating the CRT. It identifies the heater voltage and the type of...

Of course, the Ctrl+Letter keys (depending upon where the conversion is actually done) translates into codes in the range 01-1F. 00...

No idea of you can find 80C186EB/80C188EB or 80C186EC/80C188EC chips...

I also can't find a serial interface on the 80188. I forgot about the 'enhanced' product line. Good spot there... Dave

Thanks. I never like things like DRQn inputs floating. I think they can be disabled in software anyhow (so shouldn't affect the...

>>> So I need Resistors on the Output sides on the inverters? Got it! Or use a 74LS04 inverter instead - this device is not open...

This is the closest information we have found at all on any QBUS Plessey memory cards...

The UC07 card can either emulate the MSCP disk interface ***OR*** the TMSCP tape interface - but not both simultaneously. Therefore...

Yeah. If I were doing this I'd probably do one of these two things to interface the memory and skip the 8288: A: If I were *sure* I...

I will have a look tomorrow. My stupid phone will not let me open files from bitsavers... Dave