Recent posts

#1

Applications (CPC and CPC-related) / Re: XDDOS guide

Last post by Nemo59 - Today at 00:09

Thanks!

I started a French english translation. Here is work in progress

#2

Applications (CPC and CPC-related) / Re: Port of FUZIX for the CPC6...

Last post by ajcasado - Yesterday at 23:34

With this version, you can run FUZIX using only a floppy drive, as long as you have a standard RAM expansion of at least 512k and a 3.5" floppy disk drive or a device capable of emulating one well enough.

Whether this is actually useful is pretty debatable, but at the very least, it's definitely a challenge!

#3

Applications (CPC and CPC-related) / Re: Port of FUZIX for the CPC6...

Last post by ajcasado - Yesterday at 23:26

Hi,
I've managed to add support for standard RAM expansions to be used as RAM disk for swap space in FUZIX. For this purpose, I created a new platform in the FUZIX platform tree called CPC6128-SME.

The size of the RAM expansion isn't automatically detected; it needs to be set in the config.h file before compilation.

Two expansion sizes are supported: 512k and 1024k. I've uploaded the corresponding builds for both sizes to https://github.com/ajcasado/FUZIX/releases.

With this version, you can run FUZIX using only a floppy drive, as long as you have a standard RAM expansion of at least 512k and a 3.5" floppy disk drive or a device capable of emulating one well enough.

#4

Amstrad CPC hardware / Re: Replacement Z80A CPU

Last post by eto - Yesterday at 22:39

Z0840004PSC

- 1x https://www.ebay.com/itm/174313284022?hash=item2895e1a1b6:g:Rz4AAOSwS7xe4eMj
- 5x https://www.ebay.com/itm/174313289653?hash=item2895e1b7b5:g:Rz4AAOSwS7xe4eMj
- 10x https://www.ebay.com/itm/392833995040?hash=item5b76bb1120:g:Rz4AAOSwS7xe4eMj

Best price. Fee shipping, free return. Already ordered to this seller. Why searching another CPU version?

fyi: I bought a set of 10 CPUs 2 years ago from this seller and just recognized that not all of them are NMOS. I only have 6 of the 10 left but 5 of those 6 turned out to be CMOS CPUs.

Not sure what that means in general but if you have ordered CPUs from there make sure you don't have the CMOS version before installing it in a CPC.

#5

Applications (CPC and CPC-related) / Re: XDDOS guide

Last post by Nemo59 - Yesterday at 22:00

Thanks!

I started a French translation (but maybe English is better for sharing...). I need to find time for that :/

#6

Technical support - Hardware related / Re: Reliable source for NMOS Z...

Last post by eto - Yesterday at 21:54

I could test 3 different Z0840004PSC CPUs, all from the same seller, and only one of them behaved correctly. The others produced white noise when I played back music with Arkos Tracker.

I finally checked the power consumption and it was clearly different. The Z0840004PSC which plays sound correctly consumed about the same power as other NMOS Z80s. The other two CPUs (with noise instead of sound) consumed around 170mA less.

So... probably fake NMOS CPUs.

#7

Technical support - Hardware related / Re: Reliable source for NMOS Z...

Last post by Prodatron - Yesterday at 21:34

So, I can imagine the players for other Z80 computers are more safe.

Yes, because they have no PPI between the Z80 and the PSG.
On a Spectrum or an MSX you can access the PSG directly with two dedicated ports, so there is no need for OUT (C),0 to it speed up.

#8

A

Technical support - Hardware related / Re: Reliable source for NMOS Z...

Last post by andycadley - Yesterday at 21:21

Erm, this sounds like it would be a software bug in Arkos, which isn't. Original CPCs never used CMOS Z80, so the Arkos player is 100% compatible

I'm not saying it's a software bug, but that I've noticed this problem on games using this audio player on CPC when exchanging the Z80 to fix one of my computers. Arkos Tracker is a fairly recent software written when the CMOS compatibility issue was already known. So, I can imagine the players for other Z80 computers are more safe.

The trick of using OUT (C), 0 was widely known and used back in the day across most 8-bit Z80 machines, so I wouldn't be surprised to find that using a CMOS chip in any of them will lead to some odd issues (whether it's music or other stuff).

#9

E

Technical support - Hardware related / Re: Reliable source for NMOS Z...

Last post by Egg Master - Yesterday at 19:46

Erm, this sounds like it would be a software bug in Arkos, which isn't. Original CPCs never used CMOS Z80, so the Arkos player is 100% compatible

I'm not saying it's a software bug, but that I've noticed this problem on games using this audio player on CPC when exchanging the Z80 to fix one of my computers. Arkos Tracker is a fairly recent software written when the CMOS compatibility issue was already known. So, I can imagine the players for other Z80 computers are more safe. 

#10

Programming / Re: Plus sprite upload tips

Last post by Cwiiis - Yesterday at 18:18

absurd branch : when you already have a register for the data, use the register, do not explore other cases
there is many cases when you do not have the register ready to use but you can be smart
and use some auto-purge if needed, you will gain speed+memory

Right, this isn't brute-force at this point, this is a heuristic Limited depth, breadth-first and pruning the least successful branches might be a good way of limiting the search space. I wonder how much more efficient it would be vs what I'm doing at the moment though...