Thank you guys, you have calmed me. Everything is clear about 24257 SRAM. Information from the datasheets is helpful, but practical experience is at least equally important. Apart from the previously mentioned 24257 I 've also CE81256A- 20 and AC7C256-15PC, but unfortunately without datasheets.
Related ROM. Soon will come my universal programmer , and I'll see with wich ROMs it can handle. I have a lot of different DIP ROMs, both ultraviolet and flash. The latter are mostly excess capacity. In short, it will be seen later, wich are the best.

Vladimir

Well, we do know the WDC data sheets can always stand some improvement.

POC V1.1 runs at 12.5 MHz, using an ISSI IS61C1024AL SRAM. The DC characteristics for that device say among other things:

Code:

Voh   Output HIGH Voltage   Vdd = Min., Ioh = –4.0 mA   2.4    —  V
Vol   Output LOW Voltage    Vdd = Min., Iol =  8.0 mA    —    0.4 V

Vih for the 65C816 is rated at Vdd × 0.8, which would be 4 volts, some 1.6 volts above the SRAM's Voh rating of 2.4. Granted, Voh is a minimum, but I doubt that it rises to the level of the 65C816's Vih rating. Something doesn't compute, yet the system works and is 100 percent stable.

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

The same is true for may ROMulus the 2nd using a AS6C4008 55ns 512kbyte CMOS RAM in DIP-32 together with a W65C816 running at 11.0592MHz. The AS7C256A-10T (a 5v 32kbyte SRAM) on the W65C02SXB has exactly the same values for Voh as BDDs and my RAM. I really doubt that the inputs of the W65C816/02 require 0.8VDD or 0.7VDD.

Hi guys!
Thank your friendly help, the study of PLD goes well. Simple mode already mastered (I mean ATF16V8), but registered and complex ones cause questions.
Wich variable extensions (.oe, .d, etc.) are applicable to my device?
The WinCUPL users manual says:
"...To know what extensions are available for a particular device, use CBLD with the -e flag..."
I can not find the CBLD . Does anyone know what this is?


Thanks

Vladimir

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