19 Aug
2013
19 Aug
'13
2:05 p.m.
Tony
Read Eric and my later post. He corrected me.
Intel was clever at selling half bad parts.
The one I loved was their 2758 ( maybe 2508 ) parts.
These were cataloged as "5 volt only 2708's"
to compete with TI's 2508's
What they really where was half bad 2716's.
They were even marked with a H or L for the
address bit.
What I loved best about it was that the 2758's
were selling for $32 while the 2716 parts were
selling for under $4.
That, I call good marketing.
Dwight
From: ard at p850ug1.demon.co.uk
Subject: Re: Anyone need an Intel 8035? (MCS-48)
To: cctalk at classiccmp.org
Date: Mon, 19 Aug 2013 20:54:41 +0100
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