My old ZX81 restored to full function

[revivalstudios]

Btw. The games are both out now, and the trailers are online for anyone interested.

avalanche -> http://www.revival-studios.com/?page=129
mayhem -> http://www.revival-studios.com/?page=132

[gertk]

Looking very good!
I assume you have them for sale at Apeldoorn the 30th too ?

[revivalstudios]

Yes, as well as my new ZX81 game, called: Down!

[gertk]

Yes, as well as my new ZX81 game, called: Down!

Great, I will bring my NXP81 maybe we can test it on it too.

[revivalstudios]

Yes, as well as my new ZX81 game, called: Down!

Great, I will bring my NXP81 maybe we can test it on it too.

Great, once the system is all bugfixed i'd be interest in one too ;-) Does the essentials demo work on it?

Also, the modded VP+ i bought from you has issues with the VP+ background (random garbled scanlines in the VP+ graphics), if i can find some spare room in my C3 i could bring it and give it to you. If easy to do, you can also fix composite out so i could use it on my projector.

Martijn

[gertk]

Yes, as well as my new ZX81 game, called: Down!

Great, I will bring my NXP81 maybe we can test it on it too.

Great, once the system is all bugfixed i'd be interest in one too ;-) Does the essentials demo work on it?

A lot of programs work, some of the programs which use UDG work also (like HR-GALAXIAN)
The emulation so far is rock solid but not cycle perfect, I still need to implement the proper joystick routines, if I can find the time I will add ZXpand joystick emulation and maybe even sound emulation is possible.

Also, the modded VP+ i bought from you has issues with the VP+ background (random garbled scanlines in the VP+ graphics), if i can find some spare room in my C3 i could bring it and give it to you. If easy to do, you can also fix composite out so i could use it on my projector.

I will bring a working G7400 with RGB and CVBS along, we can swap them and I can repair/modify yours.

[revivalstudios]

A lot of programs work, some of the programs which use UDG work also (like HR-GALAXIAN)
The emulation so far is rock solid but not cycle perfect, I still need to implement the proper joystick routines, if I can find the time I will add ZXpand joystick emulation and maybe even sound emulation is possible.

Sounds good! Personally i am not fond of things like UDG that only work with hardware modifications. That is the same beef i have with the msx-scene where they keep adding new and new hardware to make things into a lite-pc while still calling it msx. Additional stuff like the zxpand is fine, but it should also work on a default configuration.

I will bring a working G7400 with RGB and CVBS along, we can swap them and I can repair/modify yours.

Sounds like a plan! I really hope it is less crowded than deurne, so i have enough time to chit-chat. I do have less tables in Apeldoorn than in deurne, so also less space to cover. *fingers crossed*

[gertk]

Sounds good! Personally i am not fond of things like UDG that only work with hardware modifications. That is the same beef i have with the msx-scene where they keep adding new and new hardware to make things into a lite-pc while still calling it msx. Additional stuff like the zxpand is fine, but it should also work on a default configuration.

Yes I also have to restrain myself adding too much stuff but then again it is all in software on the mbed (I still have no extra hardware attached to the mbed other than some resistors)

But some more details on the NXP81:

PS2 keyboard support, pressing F1 will give you the (original) ZX81 manual on screen (not quite finished yet, at the moment only text and no pictures since I can only do black and white graphics), F2 will give you a disassembler and F3 a hexdump with ZX81 characters alongside. The F1, F2, F3 and fileselector all run in 80 columns (640x240 graphics)
Also you can use the numeric keypad, and also the keys like +/= quote etc. can be entered directly.
You can use the original keyboard of the ZX81 but the 80 column screens (F1/F2/F3 and fileselector) are not accessible/usable then (yet...)

Sounds like a plan! I really hope it is less crowded than deurne, so i have enough time to chit-chat. I do have less tables in Apeldoorn than in deurne, so also less space to cover. *fingers crossed*

If it is anything as 'crowded' as the former event in De Matenhal then space is not really a problem, power is... 

Do you have a (spare) VGA monitor with you ? I will bring along a G7400 and my 'miniature' VGA monitor/TV and a PS2 keyboard anyway just to be sure.

[revivalstudios]

GertK:
I only have my default 22" TFT with me which you can connect it to. If you want you can bring a regular tv for my zx81, because even a small TV is hard for me to transport (remember all my stuff needs to fit into a small C3 car ;-)

Would be great if you could add support for the old Z80-rom on your system too. Not that it is mega-useful but i always wanted some kind of switch for that on my own zx81 (talking about switches, bless the reset-switch on the Zxpand)

[gertk]

GertK:
I only have my default 22" TFT with me which you can connect it to. If you want you can bring a regular tv for my zx81, because even a small TV is hard for me to transport (remember all my stuff needs to fit into a small C3 car ;-)

I will bring my 7" LCD monitor/TV, no problem, it has CVBS, VGA, YUV and aerial/RF input (unfortunately no RGB scart).

Would be great if you could add support for the old Z80-rom on your system too. Not that it is mega-useful but i always wanted some kind of switch for that on my own zx81 (talking about switches, bless the reset-switch on the Zxpand)

The NXP81 is resettable by Ctrl-Alt-Delete :-) But I need to add a true reset switch for the mbed accessible from the outside just in case...

Rom space I have plenty (512k) so adding ZX80 support is a viable option, and storage is also no problem (SD card) and that is also where the manual is stored, it is possible to add even more books. On the RaspberryPi this will be much easier as it has more RAM, a full color output etc but at the moment I started with the mbed my RaspberryPi was still in backorder.

BTW, you could do miracles on the Pi in assembler  :D

[revivalstudios]

To be honest i am very dissapointed with my PI, it is way to slow to run anything useful at decent speed (xbmc, any other program that needs a slight bit of resources) and at least in theory this should be the case.

I am not at all a linux guy so i need to find a way to either install a different OS, or a linux install that doesnt need a bloathed web of other sourcecodes to compile each program (because of the way linux is setup even things likeunbuntu feel extremely bloated). I mean i programmed the GBA when i was still making games for a living, so something like a minimal MENU2X with a set of ARM-binaries would be ideal (at least with a gp2x/dingoo native i didnt need to deal with any of that linux bs).

Without the intention of offending anyone, but to me Linux is like a badly stacked tower of interweavved bricks, and you better not move or alter one or the thing will fall apart, so just add another brick on top then eh?

To be fair, OSX = Beos with fancy desktop. Windows is extremely ineffecient, used to be very unstable (i must say i have little troubles with stability of windows7) but easy to use and all closed source, so no 'prutsers' can f*&k it up.

A minimal-OS for a fixed config like the PI would be ideal (i believe sony laptops had a minimal OS with cross-media-bar in a few MB rom once). Give me a C-compiler the memory address of my keyboard, usb inputs, videomemory and soundbuffer an i am good to go.

The best thing about my pi is that it sits in a zx81 case (catching dust), i cant even have it just run a ZX81 emu (or other emus) so at least it has something to do :-(
I have all my hopes on the Ouya now. Too bad it uses android/java (essentially you are writing in an emulated environment) so they throw away about 40% of CPU power right there, but fingers crossed. The thing IS dual core so hopefully the one core left will be enough to make some decent sh*t on.

[gertk]

Yeah the RaspberryPi is in serious need of a native OS and programming toolkit.
I love Linux, use it at the office and at home but it is just way too much overhead on that CPU.
I programmed the mbed (ARM Cortex M3) in assembler for the Videopac rom emulator and it just flies (10 ns instructions...) So if I translate that to the Pi at 700 Mhz.. 
Another hurdle in the Pi is the fact that the information on the GPU is not open (yet).

There are rumours that BBC basic is ported to the Pi (native) and then it would be great if it would support the inline assembler like the CP/M and 6502 versions did. I can not imagine how fast that would run.

[gertk]

Did a bit of SM yesterday: I load-ed up 'Down' from tape into an original ZX81...  :D

7 minutes of keeping my fingers crossed until it started up nicely. I bought two cassetterecorders at Apeldoorn, a Philips NMS1515 and a Slipstream but only with the Slipstream the game would load up fine. The nice looking Philips NMS1515 did not have enough 'output', after three attempts to get 'Down' loaded I switched over to the Slipstream recorder (Found out that it has no volume control at all, and no speaker but it said on the bottom: For the Spectrum computer so at least I was 'keeping it in the family') and it went OK the first time.

Great game by the way, highly playable even with the ZX81 keyboard.

[gertk]

Added a ZXpand compatible joystick function to the NXP81 and it works great with Down and Stairrunner !

[revivalstudios]

Added a ZXpand compatible joystick function to the NXP81 and it works great with Down and Stairrunner !

Nice game! Wish i could play it on my videopac!