AFAIK the 29c and other EPROM series are not pinout identical with the 27c series. We used the 27c series because the original design of the FMPAC lite module was based on that EPROM series, we just used the PLCC32 version to save space on the board. You can buy the 27c512 EPROMs in China quite cheap. In EU they are 2.5 euro each. Still bearable.
Yes, I've found 27c series with reasonable prices, too. However this flash ROM (the 512kbit one) seems pin compatible to the 27c512? I think that 28C series is pin compatible, and also 29c series seemed pin compatible for <=256kbit.
The real question I wanted to ask is: are ROM types (EPROM, EEPROM, Flash) compatible while reading (if pin layout is compatible)?
The real question I wanted to ask is: are ROM types (EPROM, EEPROM, Flash) compatible while reading (if pin layout is compatible)?
I can't say for sure because I've never tried any other chips than 27c series. Maybe the 27s series is compatible, at least the pin assignments look the same for the 64kb chip.
I made this board and used my HX-10 as a test bench (since it already has a socketed Z80). All seems working!
I have 255 and 127 as return values and you should have the same. If you have the board version 1.2 (all boards have the version number except 1.2, so if there's no verson number, you have 1.2), the LS125 and LS74 chips must be swapped because of an error in the silkscreen.
sooooo
i found i have some of these boards laying around in a drawer somewhere and looked through this thread
its pretty confusing with all board versions and fixes and partlists
it seems i have a few version 1.2 board (same as Paralibris)
Pablibiris wrote:
Hi Alexey!
There is some problem if I use R3 as 169K resistor instead 170K? (I'm not sure the version of this board ^^)
