Recent posts

#1

General Discussion - Introductions / Re: What computer did you have...

Last post by roudoudou - Today at 06:45

From CPC 6128 I did a long jump to a 486 DX with 33 MHz, 4 MBytes of RAM, and a SVGA graphics card with a TSENG chipset that could easily be controlled also from BASIC. The storage was done with a 20 MByte hard drive. Also a SoundBlaster was available.

Especially for assembly programming on 486: Every register is an accumulator, every register is 32 bits wide, most commands are executed in a single cycle ... Z80 assembly is so much more complicated. But addressing on Z80 is simple: 16 bit registers, 64 KBytes of memory, and some additional banks to swap in. On DOS you have to work with small memory segments and six segment registers in addition to the register holding the address, also in combination with swapping in everything above 1 MByte. Only in protected mode these limits did no longer exist. But getting there was complicated ...

On DOS there was DPMI to EASILY access every memory as one linear segment in 32 bits (Watcom C + Tasm FTW)

And before DPMI, demomakers used "real" mode which was rude

#2

General Discussion - Introductions / Re: What computer did you have...

Last post by Deevee - Today at 06:43

Before CPC I had a Philips Videopac G7200

Did you have the Basic and Z80 cartridge? There was something like this for 7400 and it was probably called 7410.

There was the "Computer Programmer" cartridge G7109, but no unfortunately i did not have that. I actually knew it existed years after. I sure would have love to have it at the time! I remember I was kind of frustrated that it was not possible to program the thing.

#3

General Discussion - Introductions / Re: What computer did you have...

Last post by McArti0 - Today at 06:34

Before CPC I had a Philips Videopac G7200

Did you have the Basic and Z80 cartridge? There was something like this for 7400 and it was probably called 7410.
Your g7200 is a brilliant work of an engineer of that time because making a computer with a screen from a microcontroller is better than zx80/81

#4

General Discussion - Introductions / Re: What computer did you have...

Last post by lightforce6128 - Today at 03:54

From CPC 6128 I did a long jump to a 486 DX with 33 MHz, 4 MBytes of RAM, and a SVGA graphics card with a TSENG chipset that could easily be controlled also from BASIC. The storage was done with a 20 MByte hard drive. Also a SoundBlaster was available.

Especially for assembly programming on 486: Every register is an accumulator, every register is 32 bits wide, most commands are executed in a single cycle ... Z80 assembly is so much more complicated. But addressing on Z80 is simple: 16 bit registers, 64 KBytes of memory, and some additional banks to swap in. On DOS you have to work with small memory segments and six segment registers in addition to the register holding the address, also in combination with swapping in everything above 1 MByte. Only in protected mode these limits did no longer exist. But getting there was complicated ...

#5

General Discussion - Introductions / Re: What computer did you have...

Last post by lightforce6128 - Today at 03:44

The first digital thing I owned (or shared with my brother and my father) was a Atari 2600.

#6

Amstrad CPC hardware / Re: Amstrad CPC WiFi

Last post by eto - Yesterday at 22:46

I want a M4 board , please send me instructions for buy it.

check the first post how to get in touch with Duke. 

The prices are probably up since then, but the rest of the information is probably still valid. 

#7

G

Amstrad CPC hardware / Re: VGA through rpi pico - How...

Last post by gregg - Yesterday at 22:03

Do you have a github or a web site with more informations about the state of your work ?

Nope. I just have a messy code on my pc, and messy electronics on a breadboard. I will for sure put everything on GitHub, especially that my knowledge in electronics is really poor, so I would like to get some feedback. But first I need to clean it up at least to the point when code is readable.

As for current status - output is almost OK. Code works well, I was able to display Amstrad palette, or something close to it. I need to experiment more with resistors values to make colors better, e.g. white is a bit greenish. Input in terms of schematics is much more WIP. I am just going to order some new voltage comparators, because old ones were too slow. So far I was testing with only 1 bit per input. Except those limitations with ram, when I was trying to just use 640x200 with no border, it looks ok - just small details to improve like screen is shifted a bit, or problems with catching sync after resetting Pico with Amstrad running. So it should not be much work left.

#8

Amstrad CPC hardware / Re: VGA through rpi pico - How...

Last post by eto - Yesterday at 21:55

Nope... I am more like doing a scandoubler, just the simplified one that assumes Amstrad palette, so it is easy to use just digital pins, voltage comparators on input and 6 resistors on output.

I was considering mirroring the ram, but I got scared  double and triple buffering is just a beginning. What about reading the palette etc. That's too much for me 

ah... in that case the QL project might indeed be close to what you want to do. 

Well... I am looking forward to it :-) 

#9

Amstrad CPC hardware / Re: VGA through rpi pico - How...

Last post by genesis8 - Yesterday at 21:39

Do you have a github or a web site with more informations about the state of your work ?

#10

M

Technical support - Hardware related / Re: Blown fuse on EME-156 V dr...

Last post by mikeyp - Yesterday at 21:15

Just thought I would update that the fuse swap was successful and the drive is fully working again.

Thank you.