Search found 101 matches

by monsonite
15 Jun 2019, 13:18
Forum: Hardware and software hacking
Topic: v6502
Replies: 20
Views: 25307

Re: v6502

Marcel, Thanks for the prompt reply. I was thinking that a 30Hz frame rate might be tolerable - but anything less than that would be hard on the eyes and the brain. Films, back in the old days, were shot at 24 fps, and had a sort of motion blur, depending on the shutter angle - that gave them a soft...
by monsonite
15 Jun 2019, 08:25
Forum: Hardware and software hacking
Topic: v6502
Replies: 20
Views: 25307

Re: v6502

Hi Marcel, This is a colossal, yet worthy sub-project - and judging from your test program, you have already passed the point of proving it to be viable - Well Done! I thought that we hadn't heard from you for a while - and I happened to revisit the Gigatron Github ROM repository yesterday morning w...
by monsonite
08 Jun 2019, 09:42
Forum: Hardware and software hacking
Topic: dual ported SRAM for co-processing
Replies: 5
Views: 5069

Re: dual ported SRAM for co-processing

They are listed in the 1983 TTL Handbook - see page 2-404 in the link below http://bitsavers.trailing-edge.com/components/ti/_dataBooks/1983_TI_ALS_AL_Logic_Circuits_Data_Book.pdf It looks like they are an extended version of the 74xx670 which contained 4 x 4bit registers - which did appear much ear...
by monsonite
30 May 2019, 22:26
Forum: Escape Meta Alt Control Shift
Topic: A TTL Computer Kit from 1974
Replies: 2
Views: 4160

Re: A TTL Computer Kit from 1974

Hi Marcel, I also found the Prosser and Winkel book - and found it very interesting. To find the archive on the LD12, was the "icing on the cake". Two weeks on holiday in Portugal - I have plenty of reading time. I was not aware of the Elektor "Computer 74", but the anycpu.org ha...
by monsonite
29 May 2019, 17:18
Forum: Escape Meta Alt Control Shift
Topic: A TTL Computer Kit from 1974
Replies: 2
Views: 4160

A TTL Computer Kit from 1974

Back in Autumn 1974, the engineers at MITS in Albuquerque were busy developing what was going to become the ground-breaking Altair 8800 microcomputer - for shipment to Popular Electronics Magazine, in time for their January 1975 edition. The Altair 8800 was the first, real commercial microcomputer k...
by monsonite
06 May 2019, 18:53
Forum: Hardware and software hacking
Topic: New form factor Gigatron.
Replies: 9
Views: 9803

Re: New form factor Gigatron.

Hi All, After a few hours with EagleCAD, I have a proof of concept, reduced format pcb layout. The size is 200 x 100 mm. Power and ground planes are on the inner 2 layers, with all signals on the top or bottom layers. I have included an 8-bit output port and an 8-bit input port - as per the proposed...
by monsonite
05 May 2019, 19:14
Forum: Hardware and software hacking
Topic: Expansion bus
Replies: 98
Views: 91572

Re: Expansion bus

xopr,

I like your Tiny BASIC hack for code entry - nice.

I suppose when Tiny BASIC was written, PEEK, POKE and USR were the "tactical nukes" of the language.

I'll get a chance to try that tomorrow.

4 seconds to parse itself - is that with Mode 0 (no blank lines) video?

Ken
by monsonite
05 May 2019, 17:41
Forum: Hardware and software hacking
Topic: New form factor Gigatron.
Replies: 9
Views: 9803

Re: New form factor Gigatron.

Hi All, Attached is a PDF giving an overview of the Gigatron design. I have hypothetically split the design into two roughly equal parts, loosely called "ALU" and "Memory" and then placed the sub-systems between these "camps" so as to minimise the number of signals that...
by monsonite
04 May 2019, 20:00
Forum: Hardware and software hacking
Topic: New form factor Gigatron.
Replies: 9
Views: 9803

New form factor Gigatron.

Hi All, During the life cycle of a computer, - it is not uncommon for it to undergo a series of design changes - mainly to reduce costs or to take advantage of new technology. The classic example of this metamorphosis is the PDP-8 minicomputer, which was conceived in the era of DTL (diode transistor...
by monsonite
30 Apr 2019, 18:28
Forum: Kit assembly gallery
Topic: Assembling Gigatron the hard way
Replies: 29
Views: 22168

Re: Assembling Gigatron the hard way

Well done in tracking down your instruction error to a wiring mistake. I think you deserve to win a free pcb for your perseverance and endurance ;) I think you will make much faster progress from this point onwards - and you sure have learned a lot about the machine's instruction set and architectur...