Re: Old programmers (was: CBM-II Character Set and Colour Expansion)

Den Wed, 18 Jul 2018 12:53:43 +0200 skrev Francesco Messineo
<francesco.messineo@gmail.com>:
> I didn't want to hijack the original thread, so subject edited...
> 
> On Tue, Jul 17, 2018 at 9:12 PM, Mia Magnusson <mia@plea.se> wrote:
> 
> 
> >>
> >
> > Interesting!
> >
> > I've had trouble programming ordinary 2732's with my Hi-Lo ALL-03.
> > Had to restart the programming a bunch of times, each 256 byte
> > block (or whatever size the programmer use) would fail one or more
> > times and after some retries it would read back correct and the
> > programmer would go on to the next block and the procedure would
> > repeat.
> 
> A couple of suggestions:
> 1) Always try to match manufacturer and exact variant of the EPROM
> when programming it,
>     as it was common to change for example the Vpp or suggested
> algorithm and just add an A/B/C letter after the part number (or even
> worse, change the prefix).

I'm rather sure I selected the right manufacturer and model.

> 2)  Always verify the programmer is working well wiith respect to
> voltages and timings.
> For example, my old Hi-Lo uses an ISA card and would never respect the
> required timings if
> installed on a 486 class machine (yes, it's old) with a regular DOS
> installation.
> I had to run it under linux/dosemu that allowed me to configure a
> lower clock speed.
> Where procedures and manuals were available (like on the Data I/O
> units) I completed the test and calibration procedures making sure all
> voltages are in spec. Of course I've also checked for bad capacitors
> and other electronic faults when I acquired them.
> Particularly bad is the Digelec 824 because no manual or schematic
> could be found for it, so I can't find why it fails on some types and
> works on others.

Oh, the speed of the computer must be the problem then. I'm running it
on a Pentium 166 MMX which actually runs Windows XP, and I'm using
patched versions of the DOS software with a special driver allowing the
DOS software to access the I/O ports directly.

Too bad that I'm really no good at debugging DOS binaries. Otherwise it
would be nice to patch the delay loops.

Or what should really be done is reimplement the software but using all
existing definitions files.

I've read about a project making a new USB based interface for the HiLo
eprom programmers, but it seems noone actually did make any usable
software for ut.

Maybe I'll just have to place it in an older computer. I don't have
much left that's older than a 486 though, except a Panasonic Senior
Parther portable 8088 machine with CRT and built in printer (!). Maybe
I'll have to have a look at dosemu+linux.

Or preferable repair my broken Unisite. First the hard disk (!) in it
died, and when I tried replacing it something else broke which resultet
in it almost only saying some kind of bus error message on the terminal
port. Probably due to me not observing ESD handling procedure :/

> > I'm not really sure what causes this, I haven't really
> > investigated. It doesn't look like there are loads of bad
> > capacitors in the programmer, which could otherwise explain it.
> 
> as any other old electronic device, it must be kept in good shape :)

True :)

> > Btw I remember a friend had a programmer called "SmallProg" for
> > Amiga. It would program most cmos eprom fine, but when we tried
> > programming old 2764's it would just fail. We ended up soldering a
> > wire onto the point between it's 21V generator and the transistor
> > that switches VPP, and hooking up a small 12V lead acid battery in
> > series with +12V from the Amiga to provide about 24V DC directly to
> > the programmer, then it did burn the 2764's fine.
> 
> oh my... :)
> I started in the '80s with a locally made clone of the C64 based
> Promenade C1, it worked (and still does) fine. What I liked about it,
> is the complete configurability of voltages and algorithm, but you
> must read the part datasheet before deciding what program options you
> should use.
> It never failed a programming (unless a part was bad).

Interesting! I wish I had an eprom programmer back in the days, or knew
how to build one. Today it seems trivial and I might actually had
succeded building one back in the 80's if I had todays knowledge :)

> > I assume it would had worked changing the (proprietary) software to
> > program the eprom far slower, i.e. a short puls and then let the
> > charge pump recover from the load, instead of trying to program as
> > fast as the eproms are specified to be programmed.t
> 
> most algorithms are interactive anyway.
> Wrong Vpp (higher) is an EPROM instant killer (don't ask how I know
> it).

:O



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