19 Aug
2013
19 Aug
'13
3:54 p.m.
The 8035 is a mask rom part but that doesn't mean
Is it? The databooks I ahve (Intel and Philips, who second-sourced it)
say that the 8035 is ROMless, the 8048 is mask-ROM and the 8748 is EPROM.
The 8039/8049 and 8040/0850 are similar parts with more intenral memory.
it can't be used. If you don't need all the
I/O, there
is a pin that can be tied and you can add external
EPROM with a latch chip ( forget '374 of '373 but
'373. Link latch enable (pin 11) to ALE on the 8035, D inputs to the
AD bus. Then the outputs of this latch are the low 8 address lines.
However, what I don't know is if the 8035 has the internal ROM but it's
defective or contains a useless program. I certainly remember reading
that soem 8032s (a later Intel ROMless microcontroller, the ROMed part
being the 8052) did have a ROM containing (normally) a buggy/defective
version of 8052 BASIC. In other words ones that failed the ROM test were
marketed as ROMless.
-tony