Search found 651 matches
- 10 May 2023, 09:26
- Forum: Hardware and software hacking
- Topic: gtBASIC
- Replies: 435
- Views: 209745
Re: gtBASIC
There isn't, SPRITE's are designed to emulate real hardware sprites as much as possible, i.e. they are capable of restoring any background, static, dynamic, other sprites, blit's, bullets, etc. If you want a sprite that doesn't redraw/refresh based on spatial state, (i.e. movement), then just use a ...
- 09 May 2023, 05:04
- Forum: Hardware and software hacking
- Topic: gtBASIC
- Replies: 435
- Views: 209745
Re: gtBASIC
You need to LOAD the SPRITE's before the BLIT's. most likely what has happened is that the BLIT's have taken some of the SPRITE's memory. Also, with the 64k model the maximum number of rows for all SPRITE's, is 120 + 128; have you exceeded this number?
- 27 Apr 2023, 17:25
- Forum: Hardware and software hacking
- Topic: gtBASIC
- Replies: 435
- Views: 209745
Re: gtBASIC
There's no need to do that, the BLIT routine will automatically split up the image into contiguous chunks of whatever you specify, obviously it will become a little more inefficient as more individual native calls will need to be made internally to get the full image on screen; just set the number s...
- 27 Apr 2023, 13:11
- Forum: Hardware and software hacking
- Topic: gtBASIC
- Replies: 435
- Views: 209745
Re: gtBASIC
Sprites are hard coded to use the offscreen segments of both pages of memory, this means from 0x08A0 to 0x7FA0 for page 0 and 0x80A0 to 0xFFA0 for page 1, this means that the maximum number of combined rows of data in your sprites is 120+128, (not including PATTERN's, just LOAD SPRITE commands). It ...
- 26 Apr 2023, 23:17
- Forum: Hardware and software hacking
- Topic: ROM switching:
- Replies: 12
- Views: 8295
Re: ROM switching:
You'll probably get away with no de-bouncing, but it is poor design practice; you'll be resetting the 161's multiple times, at the mercy of whatever switch you decide to use.
- 26 Apr 2023, 16:08
- Forum: Hardware and software hacking
- Topic: ROM switching:
- Replies: 12
- Views: 8295
Re: ROM switching:
When switching ROM's, unless the current native code path is the same, (between the previous ROM and the new ROM), the Gigatron will most certainly have timing issues and/or most likely crash.
You will need some sort of reset to initialise the PC to 0x0000.
You will need some sort of reset to initialise the PC to 0x0000.
- 25 Apr 2023, 17:51
- Forum: Hardware and software hacking
- Topic: ROM switching:
- Replies: 12
- Views: 8295
Re: ROM switching:
I was looking for a way to add an external reset to the Gigatron without having to change the hardware on the motherboard. This does not seem to be possible. The MCP100 has a push-pull output. It's only one trace you have to cut and then insert your circuit; even if you use the device bmwtcu pointe...
- 24 Apr 2023, 21:45
- Forum: Hardware and software hacking
- Topic: ROM switching:
- Replies: 12
- Views: 8295
Re: ROM switching:
Here is some more information on the original design that got lost in a different thread: Other vintage computers use writing to address 0x0, 0x1, 0x2, 0x3 to switch the bank ... For 32 and 64 kb, it's very simple: one or two D flip-flops that are set to 1 or 0 by writing to the address 0 or 1 (2 an...
- 24 Apr 2023, 21:22
- Forum: Hardware and software hacking
- Topic: ROM switching:
- Replies: 12
- Views: 8295
Re: ROM switching:
If you look at the schematic in the Gigatron manual, page 48, you'll see the MCP100 with a !RST output, then on page 49 you'll see the !RST output fed to the four 161's !MR input, (the program counter). All I did was add a de-bounced reset switch to the MCP100; when switching ROM's, (my ROM switcher...
- 24 Apr 2023, 14:03
- Forum: Hardware and software hacking
- Topic: gtBASIC
- Replies: 435
- Views: 209745
Re: gtBASIC
Can you point me to an explanation of this code: ' Defines the amount of contiguous RAM needed for blit stripes, (in this case 15*6 + 1), min address and search direction _blitStripeChunks_ 15, &h1FA0, &hFFFF, ascending Marcel's original sprite routine, (that I call a blit), is only capable...