General Category > LisaList2
New CPU, I/O, & Motherboards for Lisa 1/2 and Lisa2/10
sigma7:
--- Quote from: diogenes on September 30, 2023, 12:06:54 pm ---And can you tell me the DigiKey part # of the ROM switch? It seems to be a right angle
4 pole SPST DIP (as seen in the populated Sapient CPU board)
--- End quote ---
There are lots of possible choices for the ROM SW, so you can choose according to your preference.
The picture shows a right angle "piano" style switch, which may be the easiest style to adjust when working on the Lisa from the rear, but other styles will work fine too.
And, if you don't install any switch, it will behave as though all poles are open, which will work fine with stock/standard/original ROMs.
--- Quote from: diogenes on September 30, 2023, 12:23:35 pm ---Is this the correct DIGI KEY part# for the DIP switch?
CT1954MST-ND
--- End quote ---
That switch will work fine. The T suffix indicates it has tape over it for automated soldering equipment, so you'll peel that off. If the same switch was in stock without the T it might be a few cents cheaper.
That brand is a light blue colour. Other brands in stock are priced similarly and come in Black, Red, or Blue. If you have a preference, you are welcome to send me a DM and I'll help you select one.
sigma7:
--- Quote from: diogenes on September 30, 2023, 12:06:54 pm ---ROM switch? It seems to be a right angle 4 pole SPST DIP
--- End quote ---
A perhaps subtle detail is that switch 1 of the 4 is at the end closest to the 68K CPU.
Up on or Down on doesn't matter as long as you know which is which.
(IIRC there are right angle switches that are labelled in the opposite direction. A reverse numbered switch will work fine, you just need to be aware when setting it.)
The board also has a hole pattern for using a rotary DIP switch in lieu of the toggle/slide switch, but I don't know offhand which rotary switches would fit.
patrick:
The EPROMs on the CPU board should have access times of 350 ns or below. However, I have also seen 3A ROMs from Sun Remarketing with 450 ns.
The video state PROM is driven by the dotclock, so it must be faster than 50 ns.
The floppy ROM is running at Apple ][ speed, so 450 ns is sufficient.
Jon42:
I know it is probably a longshot, but worth asking anyway. Does anyone have a completed working new CPU, I/O, & Motherboard, particularly the last two? For 2/5 or even 2/10 for sale?
bmwcyclist:
Are these boards still available?
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