Search found 76 matches

by Zarchos
Mon Dec 11, 2017 9:04 am
Forum: Software & Programming
Topic: Q68 Powered Arcade Game
Replies: 29
Views: 1096

Re: Q68 Powered Arcade Game

Slightly amending the VHDL code to make this video DMA address writable would be a very interesting feature. Even if that's tempting: I'm pretty sure that modifying the hardware and everyone having a slightly different implementation in their Q68 would not help with software availability. There's e...
by Zarchos
Mon Dec 11, 2017 8:41 am
Forum: Software & Programming
Topic: Q68 Powered Arcade Game
Replies: 29
Views: 1096

Re: Q68 Powered Arcade Game

I don't get it, about video DMA. I thought you were inquiring a programmable DMA controller. Of course, data is read from SDRAM by the video controller. Slightly amending the VHDL code to make this video DMA address writable would be a very interesting feature. It is not VHDL, but schematics and Ve...
by Zarchos
Mon Dec 11, 2017 8:39 am
Forum: Hardware
Topic: Hardware of the Q68 and programming examples
Replies: 2
Views: 138

Re: Hardware of the Q68 and programming examples

Okay ! Understood. There will be much possible, I have no doubt about it. Understand that, of course, before starting programming on it, it is important to have more hardware, in-depth, knowledge. It would be a pity, not to use it from day one, if it is available. Thanks again for your time, and sor...
by Zarchos
Sun Dec 10, 2017 11:13 am
Forum: Software & Programming
Topic: Q68 Powered Arcade Game
Replies: 29
Views: 1096

Re: Q68 Powered Arcade Game

I don't get it, about video DMA. How can the visible screen be displayed on screen if there is not the reading, under DMA, of a memory area, to then, through the video chip, serialise, and sync the data to send them to a DAC then outputting RGB or VGA signals ? I can understand this video DMA addres...
by Zarchos
Sun Dec 10, 2017 9:25 am
Forum: Hardware
Topic: Hardware of the Q68 and programming examples
Replies: 2
Views: 138

Hardware of the Q68 and programming examples

Hi all. I have a series of questions about the Q68, so I thought it could be a good idea to put them under this thread. Let's go ! 1/ Q68 uses an FPGA. What is necessary to reprogram it ? I am asking that for various reasons, in particular implementing 8 bit per pixel screen modes, like 384 x 288 (o...
by Zarchos
Sun Dec 10, 2017 5:30 am
Forum: Software & Programming
Topic: Q68 Powered Arcade Game
Replies: 29
Views: 1096

Re: Q68 Powered Arcade Game

What does the Q68 offers to set the address of the video DMA ? How precise in terms of bytes is it ? Also : are the size of the borders programmable ? A list and description of all hardware registers of the video chip, and the memory controller, would be great to know what could be achieved. All thi...
by Zarchos
Sun Dec 10, 2017 5:19 am
Forum: Software & Programming
Topic: Fast plotting (and unplotting) sprites / Q68
Replies: 18
Views: 619

Re: Fast plotting (and unplotting) sprites / Q68

When I read that I can tell you definitively we'll need fast plotting and unplotting routines for the Q68, to get great and fast arcade games. My point is getting an arcade game at all, which has not happened for 20 years. Fast routines, but no game would be of little interest for me. We'll have bo...
by Zarchos
Sat Dec 09, 2017 8:23 am
Forum: Software & Programming
Topic: Fast plotting (and unplotting) sprites / Q68
Replies: 18
Views: 619

Re: Fast plotting (and unplotting) sprites / Q68

CPU access to the normal SDRAM memory is not particularly fast, as it is random access. You can expect about 100 ns per 16-bit word. (No CPU cache, therefore burst access only for video.) When I read that I can tell you definitively we'll need fast plotting and unplotting routines for the Q68, to g...
by Zarchos
Fri Dec 08, 2017 3:59 pm
Forum: Software & Programming
Topic: Fast plotting (and unplotting) sprites / Q68
Replies: 18
Views: 619

Re: Fast plotting (and unplotting) sprites / Q68

This is great Peter, in particular if the faster than expected opcodes are the ones accessing memory.
I am really impatient to get the beasties and experiment.
And yes you had already specified only high resolution screen modes slow down the Q68.
Sorry for the waste of time.
by Zarchos
Fri Dec 08, 2017 1:42 pm
Forum: Software & Programming
Topic: Fast plotting (and unplotting) sprites / Q68
Replies: 18
Views: 619

Re: Fast plotting (and unplotting) sprites / Q68

My interest would be to see a new arcade game at all. As far I can remember, this has not happened for the QL in about 20 years. The original QL was already fast enough for arcade games. So a machine which is roughly 20 times faster (Q-Top benchmark) does not technically need highly optimized sprit...

Go to advanced search