Search found 176 matches

by bprosman
Sun Sep 16, 2018 11:33 am
Forum: hardware
Topic: My first (large) CPLD steps (XC9572)
Replies: 7
Views: 173

Re: My first (large) CPLD steps (XC9572)

Thanks for the quick responses. - XC9572 - needs a 5V supply - XC9572XL - needs a 3.3V supply (I/Os are 5V tolerant) Ok so that is clear. With regards to the decoupling caps, I put some on, though I tied the VccLogic's together as well as the VccIO's . And put a cap on both. Hope that is sufficient....
by bprosman
Sun Sep 16, 2018 9:03 am
Forum: hardware
Topic: My first (large) CPLD steps (XC9572)
Replies: 7
Views: 173

My first (large) CPLD steps (XC9572)

Good morning, To replace "glue logic" in my CPU boards (to be designed) im working with XC9572 and the EPM3064. Even though I know they are obsolete ,the TQFP packages are still widely avaialable. With the EPM3064 I made a memory decoder but that was all done by "schematic entry" now my first steps ...
by bprosman
Fri Sep 14, 2018 10:43 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 275
Views: 10254

Re: RGB to HDMI using a Pi Zero and a small CPLD

Maybe a weird/dumb question but can this also be used to create an Atom "color board" ?

Kind regards, Bram
by bprosman
Wed Sep 12, 2018 10:00 pm
Forum: acorn atom
Topic: Atom 2k18 ?
Replies: 63
Views: 1899

Re: Atom 2k18 ?

These guys do a lot in custom keyboards :
http://www.maxkeyboard.com/products/
by bprosman
Tue Sep 04, 2018 1:03 pm
Forum: acorn atom
Topic: Building an Acorn System 1
Replies: 24
Views: 902

Re: Building an Acorn System 1

@Kazzie,

Do you want to stick to the original using the proms ?
As you could consider throwing in some pals/gals.

Kind regards, Bram
by bprosman
Tue Sep 04, 2018 5:30 am
Forum: acorn atom
Topic: Building an Acorn System 1
Replies: 24
Views: 902

Re: Building an Acorn System 1

(If I expand this System 1 into a rack-based System 2 in the future, I'll probably have a go at wire wrapping the backplane: I have several wire-wrap DIN41612 sockets, and a wire wrap tool sat in a toolbox.) For these kind of projects I've designed and ordered a bus board as well as an extender car...
by bprosman
Sun Sep 02, 2018 7:52 am
Forum: off-topic
Topic: Other RC2014 owners
Replies: 10
Views: 354

Re: Other RC2014 owners

First of all I like the RC2014 design, its flexibility etc. However i dont like the wobbly single row connector design.
RDK used it as well in his early NDR computer design.
http://www.ndr-nkc.de/compo/z80/cpuz80.htm
by bprosman
Thu Aug 30, 2018 2:15 pm
Forum: acorn atom
Topic: Atom Hardware Advice Needed
Replies: 38
Views: 457

Re: Atom Hardware Advice Needed

I would replace the dodgy white sockets by professional ones.
If youre not that experienced I would do it one by one, to avoid making a mistake and not knowing which socket it was.

Kind regards, Bram
by bprosman
Tue Aug 28, 2018 7:42 pm
Forum: acorn atom
Topic: Atom 2k18 ?
Replies: 63
Views: 1899

Re: Atom 2k18 ?

What I wonder about is why do these "Alternative keyboard" emulate switches, why not "reading" the 7445 and injecting a column signal into the 8255. Timing wise a little more tricky but then can be done with just one microcontroller.
by bprosman
Mon Aug 20, 2018 11:59 am
Forum: acorn atom
Topic: Acorn Atom on Eurocard
Replies: 8
Views: 502

Re: Acorn Atom on Eurocard

For those knowing their classics might recognize my (partial) Kicad drawing :wink:
AcornAtom.JPG
by bprosman
Wed Aug 08, 2018 10:25 am
Forum: other vintage computer hardware, software and games
Topic: Elektor Junior Computer Revival
Replies: 1
Views: 171

Re: Elektor Junior Computer Revival

Version 0.0 of the schematic is there. Let the checking begin.
Elektor Junior V0_0.pdf
(110.52 KiB) Downloaded 24 times
by bprosman
Thu Aug 02, 2018 4:27 pm
Forum: other vintage computer hardware, software and games
Topic: Elektor Junior Computer Revival
Replies: 1
Views: 171

Elektor Junior Computer Revival

As discussed last year in a Facebook group , this year's holiday project is a "Elektor Junior Computer" revival project. This means I will redesign the original Elektor PCB , in Kicad and will order a few from JLCPCB. I have contacted Elektor about this and as long as I only "sell" these PCB's to fr...
by bprosman
Mon Jul 23, 2018 9:07 pm
Forum: acorn atom
Topic: Atom 2k18 ?
Replies: 63
Views: 1899

Re: Atom 2k18 ?

What Spartan board are you referring to Roland ?
by bprosman
Wed Jul 18, 2018 10:35 pm
Forum: acorn atom
Topic: Acorn Atom on Eurocard
Replies: 8
Views: 502

Re: Acorn Atom on Eurocard

Hi Phil,

Would love to see your files as a starting/inspiration point. Especially the keyboard stuff.
The AtomMMC definitively will be included.

Colour video is a wish but not sure what workable options there are if I want to go Godil-less

Kind regards, Bram
by bprosman
Mon Jul 16, 2018 5:59 pm
Forum: acorn atom
Topic: Acorn Atom on Eurocard
Replies: 8
Views: 502

Re: Acorn Atom on Eurocard

Let me contact him .
by bprosman
Mon Jul 16, 2018 1:51 pm
Forum: acorn atom
Topic: Building an Acorn System 1
Replies: 24
Views: 902

Re: Building an Acorn System 1

Nice built.
I am looking of maybe building an Atom on 100x160mm Eurocards.
This one is nice as well though.
Only thing is the "bubbly displays" seem to become rare.

Kind regards, Bram
by bprosman
Sun Jul 15, 2018 4:18 pm
Forum: acorn atom
Topic: Acorn Atom on Eurocard
Replies: 8
Views: 502

Acorn Atom on Eurocard

Following Rolands 2K18 discussion, built his previous model I was wondering if there would be interest in building an Atom on 19" Eurocard boards. New meets old.. using the 6847 (No godil) but a PS/2 keyboard interface. Split over maybe multiple boards, and for the Glue Logic I want to use the EPM30...
by bprosman
Sun Jun 24, 2018 7:16 am
Forum: acorn atom
Topic: YARRB
Replies: 119
Views: 7232

Re: YARRB

Hi Roland,

Having bought one of your YARRB boards I took the liberty to redraw the schematic a bit.
If you want to have the Kicad files let me know, I can also add them here.

Kind regards, Bram
by bprosman
Fri Jun 15, 2018 1:07 pm
Forum: acorn atom
Topic: Atom 2k18 ?
Replies: 63
Views: 1899

Re: Atom 2k18 ?

but whatever I try, it's always too big. Did you try rotating the chip 45 degrees ? Especially for Roland : special plice :-) https://nl.aliexpress.com/item/XC9572XL-15PCG44C-XC9572XL-15PC44C-XC9572-15PCG44C-XC9572-15PC44C-XC9572-XC9572XL-PLCC44-500pcs-lot-Free-Shipping/32803422554.html?spm=a2g0z.s...
by bprosman
Sun Jun 10, 2018 1:12 pm
Forum: acorn atom
Topic: Recovered ROM.
Replies: 1
Views: 226

Re: Recovered ROM.

Seem to be used to drive an ignition coil or something : REM------------------ REM OUTPUT ON PB7 REM------------------ DIM A(1) REM ARRAY POINTERS GOSUB 400 REM--ASSEMBLE P."" P."INPUT DURATION AND FREQUENCY"' P. "OF EACH SPARK"'' ( INPUT"NUMBER OF STEPS"S 2 IF S<1 GOTO 10 7 P.' < DIM TT(S),HH(S),GG...
by bprosman
Sun Jun 10, 2018 1:07 pm
Forum: acorn atom
Topic: Atom 2k18 ?
Replies: 63
Views: 1899

Re: Atom 2k18 ?

Also the 44 pin VQFP XC95xxXL CPLDs are not that difficult to solder, and would have the advantage that the existing CPLD code could be re-used. Maybe it shows my age but personally also would not go the FPGA route. Would even consider bringing back the good old 6847. (but then you lack the color o...
by bprosman
Sun Jun 03, 2018 8:19 pm
Forum: hardware
Topic: Eprom access times
Replies: 1
Views: 148

Eprom access times

Does anyone know what the minimum access speed is for Eproms in a BBC-B and/or an Acorn Atom ?

Kinds regards, Bram
by bprosman
Sat Mar 24, 2018 7:20 pm
Forum: acorn atom
Topic: Acorn Atom newly acquired not resetting
Replies: 19
Views: 992

Re: Acorn Atom newly acquired not resetting

Lots of potential for loose connections and bad joints.
Indeed I see a lot of single sided IC sockets.
by bprosman
Tue Mar 06, 2018 9:06 pm
Forum: hardware
Topic: Z80 Monitor
Replies: 0
Views: 445

Z80 Monitor

Anyone aware of a nice re-usable Z80 monitor preferrably with a 8251 ?.
I have found this one, very nice piece of work but unfortunately not with source.
I'd like to re-asseblemble , tinker with it.
http://www.instructables.com/id/Z80-Mon ... m-and-SBC/
by bprosman
Thu Dec 28, 2017 3:23 pm
Forum: acorn atom
Topic: Happy Holidays! :)
Replies: 2
Views: 522

Re: Happy Holidays! :)

Happy holidays !!
by bprosman
Fri Dec 22, 2017 4:50 pm
Forum: acorn atom
Topic: ICE T65/Z80/6809
Replies: 644
Views: 45443

Re: ICE T65/Z80/6809

May welldesolder and replace with right angle ones.
Too bad the straight ones are out of pitch , so yes you more or less have to.
by bprosman
Thu Dec 21, 2017 7:05 am
Forum: acorn atom
Topic: ICE T65/Z80/6809
Replies: 644
Views: 45443

Re: ICE T65/Z80/6809

Got my 2nd EEPizza board in and it came with a straight single header row like the 1st one.
by bprosman
Sat Dec 02, 2017 9:00 am
Forum: acorn atom
Topic: ICE T65/Z80/6809
Replies: 644
Views: 45443

Re: ICE T65/Z80/6809

I ordered a 2nd one so curious what i get. My first one was the same as yours.

Regards, Bram
by bprosman
Wed Nov 01, 2017 8:37 am
Forum: hardware
Topic: Would anyone mind burning me a Starstick ROM?
Replies: 12
Views: 750

Re: Would anyone mind burning me a Starstick ROM?

Hi Commie_user,
If you (via PM) send me your postal address I will burn you one or two.
Has to come from NL though.

Regards, Bram