7 Dec
2006
7 Dec
'06
8:10 p.m.
The downside, of course, is that as the
hobbyist-end-user, you are
somewhat out in the cold if you don't own a GAL programmer. They can
easily run to hundreds of dollars for basic ones, and, unlike an old
4K EPROM, they are not trivial to make programmers for from scratch.
There are no excuses .. http://www.geocities.com/mwinterhoff/galblast.htm
Lee.
7 Dec
7 Dec
8:16 p.m.
On 12/8/06, Lee Davison <lee at geekdot.com> wrote:
Very nice. I may have to look into that as a replacement for my ancient UP600a.
I'd personally look into taking the path of an external bench +24VDC
supply, but I can see how it'd be handy to have it all self-contained.
Has anyone on the list built that one?
-ethan
The downside,
of course, is that as the hobbyist-end-user, you are
somewhat out in the cold if you don't own a GAL programmer. They can
easily run to hundreds of dollars for basic ones, and, unlike an old
4K EPROM, they are not trivial to make programmers for from scratch.
There are no excuses .. http://www.geocities.com/mwinterhoff/galblast.htm 
8 Dec
8 Dec
3:45 a.m.
Ethan Dicks wrote:
On 12/8/06, Lee Davison <lee at geekdot.com>
wrote:
Yep: <http://www.philpem.me.uk/elec/galblast/>
Mine's based on a variant of the design that was slightly cheaper to build.
74HC573 latch, resistor-ladder DAC, opamp, KA34063 (=MC34063) based switching
PSU, a pair of 7407 O/C buffers, a 7805, some resistor packs and a few passives.
The one thing I am going to do is replace the diode voltage dropper with a
proper 3.3V regulator - should be an easy mod (steal GND from the 7805, Vin
There are no excuses ..
http://www.geocities.com/mwinterhoff/galblast.htm
Very nice. I may have to look into that as a replacement for my ancient
UP600a.
I'd personally look into taking the path of an external bench +24VDC
supply, but I can see how it'd be handy to have it all self-contained.
Has anyone on the list built that one? from the top of the diode chain, Vout to the bottom of
the chain).
Since taking that photo, I've added a proper DC power jack and a slightly
beefier power switching transistor.
My 6502 computer (<http://www.philpem.me.uk/elec/6502/>), incidentally, is
stuffed full of GALs. One for each board at the moment, two on the IDE/FDD
controller (which is being redesigned to use a Xilinx CPLD).
--
Phil. | (\_/) This is Bunny. Copy and paste Bunny
classiccmp at philpem.me.uk | (='.'=) into your signature to help him gain
http://www.philpem.me.uk/ | (")_(") world domination.
13 Dec
13 Dec
4:59 p.m.
On 8/12/06 01:10, "Lee Davison" <lee at geekdot.com> wrote:
Suddenly, I might be able to fix my Commodore 65!
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
The downside,
of course, is that as the hobbyist-end-user, you are
somewhat out in the cold if you don't own a GAL programmer. They can
easily run to hundreds of dollars for basic ones, and, unlike an old
4K EPROM, they are not trivial to make programmers for from scratch.
There are no excuses .. http://www.geocities.com/mwinterhoff/galblast.htm 
6:32 p.m.
Adrian Graham wrote:
I thought that was up the spout because you didn't *have* the necessary
firmware / programmed logic for it, not because you didn't have the necessary
kit to program it...
There are no
excuses .. http://www.geocities.com/mwinterhoff/galblast.htm
Suddenly, I might be able to fix my Commodore 65!
7:03 p.m.
On 13/12/06 23:32, "Jules Richardson" <julesrichardsonuk at yahoo.co.uk>
wrote:
Adrian Graham wrote:
I thought that was up the spout because you didn't *have* the necessary
firmware / programmed logic for it, not because you didn't have the necessary
kit to program it...
Nope, Riccardo Rubini has all the necessary gubbins, I just didn't have a
GAL programmer to roll my own. This is of course assuming it's because of
that chip.......
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
There are
no excuses .. http://www.geocities.com/mwinterhoff/galblast.htm
Suddenly, I might be able to fix my Commodore 65!
6431
days inactive
6437
days old
5 comments
5 participants
participants (5)
-
classiccmp＠philpem.me.uk -
ethan.dicks＠gmail.com -
julesrichardsonuk＠yahoo.co.uk -
lee＠geekdot.com -
witchy＠binarydinosaurs.co.uk