if u know cheaper more reliable programmers or erasers post them please... ur post will help me alot
The Minipro is one of the cheapest and is pretty reliable. Watch out though because they have apparently been 'cloned' and the fakes may not work as good.
I got a cheap nasty eraser from eBay which actually works fine. However for the same price you could buy several EEPROMs, which program faster and erase in a few seconds. 'Vintage' W27C512 EEPROMs sell on eBay for ~$1 each including postage. Unlike more modern EEPROMs these come in a 28 pin DIP package which is easier to work with.
I used a 28F101 in PLCC for the prototype of my current Z80 project. The PLCC socket was a pain to wire up and the chip is not easy to remove, and every now and then I have to sandpaper the pins to get good contact. I changed to the W27C512 for the production version of my project.
I will certainly use the MB8464A SRAM
Yes that should be fine. You could map the ROM to the lower 48k and the RAM to the upper 8k, or allocate 32k to each and then you would be able to upgrade to 32k RAM later on.
for the "way to load the 'data' into it." to the NSC800 computer I will use SCN2661BC1N28 EPCI to load the program to ram from my computer through a USB bridge similar Grant Searle Z80 design.
In that case you just need to modify Grant Searle's code to work with the SCN2661. This may take a bit of trial and error to get working, so using an EEPROM would be a good idea (having to wait 20 minutes to erase your UV EPROM makes for a very slow development cycle!).
will this reduction in propagation delay have any effect on a multiplexed bus processor, if so is it bad or good, if its bad how can I fix it?
Short propagation delays can be a problem if the memory responds too quickly and violates setup and hold times. However I don't think that will be a problem with the NSC800 as the bus timing doesn't appear to rely on long propagation delays. Another potential problem is noise on the bus caused by fast transitions. Make sure you have good low resistance ground wiring and power supply bypass capacitors on every chip.