*** M E M O R U M ***

What do the asterisks in your boolean formula mean? AND, I guess. Also, there doesn't appear to be an IC9 on the photo I posted of the chopped off FDX card. So maybe this is another function of the PLA, or am I missing something? Jon Yes the asterisks mean AND. It is very likely that the PAL on the...

Thanks Dave

PM and email sent

Mark

Bill of Materials Draft U1 74HCT32 or 74LS32 U2 74HCT00 or 74LS00 U3 74HCT30 or 74LS30 U4 Flash "ROM" 29F040 U5 74HCT374 (preferred) U6 74HCT138 or 74LS138 C1 100nF C2 100nF C3 100nF R1 4.7k 5% or 1% 250mW (¼W) or 0.6W metal film R2 4.7k 5% or 1% 250mW (¼W) or 0.6W metal film R3 4.7k 5% o...

Well done!


So when are you going to send me a sample board?

Mark

There are also black "rubber" like pads on either the bottom of the PCB and/or inside bottom of the case. These sometimes do not want to separate. Combined with the friction between the edge of the PCB and the case, this can make it difficult to slide the PCB along.

Mark

Dave wrote:the chips are FREE, but the information is 200 Euros


(I will dig out the info and e-mail it to you over the weekend)

Sounds a bit fishey to me

Mark

JonB wrote:..and a Cambridge Z88 though I'm buggered if I can think want to do with it.

Play with BBC BASIC, Z80 style
Also if you live in a part of the country where the mains power fails, a battery powered Z88 can be an aid to computer addicts when your laptop battery runs down

Mark

The video board actually converts the +12V supply (from the 7812) to a +5V supply for its own use. So yes, a fault in the 7812 or its smoothing capacitors could produce screen distortion or interference. Most modern 7805 regulators can replace the 7805 regulator on the MTX. There is nothing special ...

The function keys are the most likely suspects. Next, the numeric keypad / curser keys. On one of my MTX machines, I found one key that was held partly pressed down by the metal faceplate because the PCB was not correctly lined up. On another of my machines, I found that a funtion key appeared to ha...

All this talk of PETs and comments like "GRRRRRRREAT!" make me wonder if a honey monster or large animated sugar puff are going to invade the forum :mrgreen: In the unlikely event that I find some free time to play with, sorry scientifically test my REMEMOrizer with the various LCD and CRT...