Retroleum

Random updates

Phil — Sat, 21 Jan 2012 15:04:22 +0000

V6Z80P and EZ80P development continues… Work over the past few months has mainly been software related: FLOS, the V6Z80P’s default OS has been improved quite a lot with 2x-3x faster file loading, script handling, programmable function keys added as well as many small additions and improvements (with similar changes being made to PROSE too.) I’ve also made a native Z80 commandline assembler and an improved text editor allowing programs to produced in situ on the V6Z80P without a PC ‘umbilical’ if desired.

EDIT: 9th Feb: Parts are now on order for another batch of V6z80Ps – see this page for details.

EZ80P bits..

Phil — Thu, 06 Oct 2011 16:10:48 +0000

I’ve been improving the EZ80P’s default config (AMOEBA) a bit lately.. I’ve given the original token sprite system a bit of a once-over and it’s now able to support 128 sprites on screen without software multiplexing (40 sprites on any one line). Also added the option to line and pixel double the sprites and added a sprite-to-background priority system.

Have also improved the sound system - each of the 8 channels now has a loop flag which can cause an interrupt if desired, allowing samples larger than available memory to be played.

Cycle Perfect Spectrum 48 Emulator complete

Phil — Thu, 22 Sep 2011 16:13:30 +0000

Alessandro Dorigatti has completed his cycle-perfect Spectrum 48 emulator config for the V6Z80P! I’ve made a little kickstarter program which pre-loads the necessary files (Spectrum ROM and optionally, a .tap image or ramdump file) so the whole thing is now very easy to use. Here’s a video of it all in action – the programs shown were mainly chosen to demonstrate various technicalities..

Windows Version Of Spilep added

Phil — Tue, 26 Jul 2011 20:16:40 +0000

Off on a tangent whilst delving into the world of the FPGA, Ivan Z has made a Windows version of my 25-series Serial EEPROM programming util, SPILEP. So, if you find yourself in need of programming such a device, and DOS is too much hassle, by all means grab it – it does exactly what it says on the tin. (Tin not included).

Cycle-exact Spectrum Emulation

Phil — Mon, 18 Jul 2011 18:58:40 +0000

I’m pleased to report that there is now a cycle-exact Spectrum 48 emulator config for the V6Z80P! This core simulates a PAL ZX Spectrum 48K and supports the enhanced ULA (“64 color mode”) , a tape player and a Kempston joystick interface. The CPU clock frequency can be changed on-the-fly to 3.5MHz, 7MHz, 14MHz.

Full credit to Alessandro Dorigatti - for it is he who has twiddled the Spartan2′s bits to perfection :)
Kudos too, to Chris Smith for his book “The ZX Spectrum ULA; how to design a microcomputer” which Alessandro tells me was invaluable in making the config.

The emulator is currently a first release so requires a bit of manual set up each time its run but it works a treat and I’m sure we’ll soon have a .tap selector menu etc. BTW: There’s still some V6Z80Ps up for grabs… :)

In other news I’ve received the latest revision on the EZ8oP PCB and successfully soldered/tested it so those should become available more readily now (it’s still just me and a soldering iron, mind you:)

EZ80P

Phil — Mon, 30 May 2011 12:50:18 +0000

After a few trials and tribulations I think the EZ80P is ready for release into the wild.. What is it? Another Z80-based computer board but this time based the Zilog eZ80L92 CPU and a Spartan3 XC3S200 FPGA. I don’t really think of this as a sucessor to the V6Z80P (still have those up for grabs BTW) as it’s quite a different animal – you can read more about it here.

V6Z80P V1.1 etc

Phil — Sat, 15 Jan 2011 15:53:09 +0000

After a marathon soldering session I’ve just completed the first batch of 10 V6Z8oP v1.1 boards.. The latest revision of the PCB allows alternative oscillators to drive the CPU - this opens up more emulation possibilities. One popular request is for accurate ZX Spectrum Emulation, and this can now be achieved with the addition of a 14MHz crystal (divided down by the FPGA to 3.5MHz as per the original model Spectrum). I’ve adapted my own Spectrum Emulator config to suit and despite the fact it’s nowhere near a cycle-perfect emulator, it works quite well - there’s no longer any need for the manual speed tuning keys anyway :)

I’ve also been tinkering about with a new project. Zilog kindly sent me some free samples of their 50MHz EZ80L92 and I’ve started a project based around one of those (and a Spartan3 FPGA etc). It’s still at an early stage at present, so I’ll post more details when it’s more complete..

Updates..

Phil — Sat, 18 Sep 2010 11:36:41 +0000

Following some prompting, I’ve finally got around to converting the Original Z80 Project article from HTML to WordPress. It can be found on the Previous Z80 Projects page.

Also following some correspondence, I’ve updated my 25x series EEPROM programming util SPILEP. It now allows the status register to be written, allowing the memory protection bits to set and cleared.

V6Z80P+

Phil — Thu, 22 Jul 2010 14:01:50 +0000

I now have the parts to build some more V6Z80P boards, well it’ll be the “V6Z80P+” from now on as I’ve made a few small changes to the PCB (EG: The video out socket is now a standard VGA connector – this means I only have to make TV SCART adapter cables (if required) instead of those *and* VGA adapters.) I changed a few of the connections to the FPGA too, so it does use slightly modified config files from the original V6, but as far as software goes – everything made for the V6Z80P runs exactly the same. (I’ll continue to support both versions of the board too). If you’re interested in buying one, see this page for details.

V6Z80P Demo at Breakpoint 2010!

Phil — Fri, 09 Apr 2010 10:05:29 +0000

Daniel and Slawomir (Insane/Altair & Malfunction/Altair) made a fantastic demo (called Loopback) for the V6Z80P at the recent Breakpoint party in Germany. Great work guys!