Search found 202 matches

by at67
17 May 2018, 14:11
Forum: Hardware and software hacking
Topic: Second scanline disable for double the performance:
Replies: 4
Views: 1890

Re: Second scanline disable for double the performance:

What's the catch? You borrowed an instruction from the sound generation that it wants back :-) The wiped out instruction helps with creating different harmonics, duty cycle etc: the 'wavA' channel modifier. Maybe also needed for making better noise waveforms (although 'wavX' could be enough for tha...
by at67
17 May 2018, 01:15
Forum: Hardware and software hacking
Topic: Second scanline disable for double the performance:
Replies: 4
Views: 1890

Re: Second scanline disable for double the performance:

Here's the code for videoC, (5 new instructions, old means unchanged), combined with the videoB code above and the fact that videoD is disabled by default; you have 3 blank scanlines. https://youtu.be/rt34cNLT-E8 videoC .ld [$03] ; old $01d4 $0103 .ora $0f ; old $01d5 $400f .anda [$14] ; old $01d6 $...
by at67
16 May 2018, 07:02
Forum: Hardware and software hacking
Topic: WIP: Tetris + any GCL tips?
Replies: 29
Views: 8869

Re: WIP: Tetris + any GCL tips?

A quick edit, in case anyone wants to try it out, it's here (this file will probably update as I work on it): https://www.dropbox.com/s/oshibfempa9d38g/Gigatris.gt1?dl=0 The first external .gt1 file I have tested in my emulator! (apart from blinky :P) Looks and works great, but it only starts maybe...
by at67
15 May 2018, 13:57
Forum: Hardware and software hacking
Topic: WIP: Tetris + any GCL tips?
Replies: 29
Views: 8869

Re: WIP: Tetris + any GCL tips?

That sounds pretty cool, so where is the video and when do we get to play it?!?!
by at67
14 May 2018, 15:10
Forum: Hardware and software hacking
Topic: Double your RAM:
Replies: 6
Views: 5099

Re: Double your RAM:

Cheers, I'll throw some links in, looks like [img] is somehow broken even though it says it is on.
by at67
14 May 2018, 15:08
Forum: Hardware and software hacking
Topic: WIP: Tetris + any GCL tips?
Replies: 29
Views: 8869

Re: WIP: Tetris + any GCL tips?

In your clone, if you have no copies, I'm interested in knowing how you shift the board down when you get lines in a space-efficient way - most of my decisions have been constrained by having to fit code within a page (or usually less) of memory. When I see a complete line, I then copy each line fr...
by at67
14 May 2018, 14:48
Forum: Hardware and software hacking
Topic: Double your RAM:
Replies: 6
Views: 5099

Double your RAM:

This one is pretty simple and given that most of you have soldered and built your own Gigatron's should be a breeze: but once again *NOTE* I am not responsible for anything that happens should you attempt this. The Gigatron TTL comes standard with 32Kx8 of 55ns-70ns SRAM, upgrading it to 64Kx8 is tr...
by at67
14 May 2018, 13:10
Forum: Hardware and software hacking
Topic: Second scanline disable for double the performance:
Replies: 4
Views: 1890

Second scanline disable for double the performance:

Disabling scanlines on the Gigatron is not just a retro feature, it's also a method to allow the vCPU interpreter and SYS function calls access to more CPU cycles. From my initial testing disabling one extra scan line allows for 100% more vCPU and SYS cycles, (i.e. double the speed as tested by Mand...
by at67
14 May 2018, 12:57
Forum: Hardware and software hacking
Topic: PS/2 keyboard hookup with microcontroller
Replies: 14
Views: 5618

Re: PS/2 keyboard hookup with microcontroller

This seems to be the simplest and most non intrusive method, compared to modifying Gigatron hardware and firmware and then most likely suffering from missing features and/or performance issues.
by at67
14 May 2018, 11:59
Forum: Hardware and software hacking
Topic: WIP: Tetris + any GCL tips?
Replies: 29
Views: 8869

Re: WIP: Tetris + any GCL tips?

I've been working on Tetris for the Gigatron (On emulator: https://youtu.be/BATJq6sy6eM On device: https://youtu.be/6YYSNdGqg_0) and it's going ok so far, all the basic building blocks are there now (excuse the pun), and it's mostly a case of polish. The game is currently about 6k, which is mostly ...