Recent posts

#1

A

Programming / Re: Bootstrapping from FAT for...

Last post by andycadley - Today at 16:30

In that case I will have to resort to some hideous CALL trickery, because |CPM only works with drive A and I need drive B.
Hopefully I can come up with something that is short enough to be usable.

I'm not really sure you need any trickery. You can just RUN a binary file, provided the header is correctly set up for it.

#2

B

Programming / Re: Bootstrapping from FAT for...

Last post by Benedikt - Today at 15:59

But you can always reserve clusters on a FAT device using the FAT itself without assigning them to a file (a PC then may want to repair the disc ).

Reserving clusters by putting a file there sounds like a more intuitive and more robust option.
Ideally a hidden, write-protected system file or something.

The only way from BASIC is |CPM which loads track 0, side 0 sector &41. It will only load 512 bytes though (whatever is booted is then expected to load the rest).

In that case I will have to resort to some hideous CALL trickery, because |CPM only works with drive A and I need drive B.
Hopefully I can come up with something that is short enough to be usable.

#3

Games / Re: Adapting loading screens t...

Last post by Shaun M. Neary - Today at 15:23

I always really liked the original CPC loading screen, even if Trantor looks like David Lee Roth! 
Your new version looks great.

Oh thanks. Now anytime I load that up, all I'll hear is "This... must... be... just... like... living in par-a-dise!", and that was overplayed enough in 1988 

#4

Technical support - Hardware related / Re: CPC 6128 - white screen, b...

Last post by McArti0 - Today at 14:30

48Msps
Although zt-703 and ... I dreamed about Rigol

#5

M

Technical support - Hardware related / Re: CPC 6128 - white screen, b...

Last post by mmldrm - Today at 14:29

Bryce.

Ouch. That would be a bit disappointing. It's the one suggested on page 2 of this thread. 

The spec shows 10MHz. Am I misunderstanding it? (Quite possible.)

#6

Programming / Re: Rasm Z80 assembler

Last post by HAL6128 - Today at 14:27

Hello @roudoudou,

just two quick questions maybe I don't exactly understand your docu in RASM regarding calling a struct:

It says:

STRUCT nom_du_prototype, nom_de_la_variable / ENDSTRUCT

When STRUCT is used with 1 parameter (name), the following labels will be used to declare the structure, in particular its indexes 
When STRUCT is used with 2 parameters (type_name+struct_name), a structure is created of type_name and will be called structure_name
Although RASM allows you to put anything inside the declaration of a structure, the practical use is to declare labels and via the data definition instructions, a field size. It is not necessary to fill in a value in the DEF

Code Select Expand

struct st1
  ch1 defw
  ch2 defb
endstruct
struct metast1
  struct st1 pr1
  struct st1 pr2
endstruct
struct metast1 bigst ; instanciation de metast1 en bigst
ld hl,bigst.pr2.ch1 ; récupération de l'adresse absolue d'un membre de bigst
ld a,(hl)
ld a,(ix+metast1.pr2.ch1 ; utilisation de l'offset du champ via la définition de la structure (pas besoin d'instancier pour cet usage)
Q1: This part "ld hl,bigst.pr2.ch1" refers to second pointer (first struct) of the second pointer (second struct) included in the second struct? It's nested somehow, isn't it?

Q2: Is there also a D24 (3 byte member) within RASM struct available?

#7

Technical support - Hardware related / Re: CPC 6128 - white screen, b...

Last post by Bryce - Today at 14:18

Finally the 74LS02 has arrived!

I will try the above tests too, if I understand them. 

My oscilloscope is a Zoyi ZT-702S: https://zoyitools.com/product/zt-702s/

I found it for £43, and figured it's something I can use for years after this. This is true for the breadboard and components I bought for the tests - I like playing with electronics and would like to do more hardware projects in the future.

If these tests from @McArti0 can reduce the number of chips that I desolder and replace, I am less likely to destroy the motherboard in the process. Unorthodox, but I'm happy to proceed with caution on this.

Thanks for staying with me this far on the journey. I know there is a variety of opinions on the path we have taken.

The scope is ok for basic "signal present" checking, but only up to about 3MHz for proper diagnosis. That's a bit on the low side even for retro computer repair.

Bryce.

#8

M

Technical support - Hardware related / Re: CPC 6128 - white screen, b...

Last post by mmldrm - Today at 13:43

Ok. Make OR Gate on breadbord. (From 2 NOR gate in 74Ls02).

I could do this when I was 18. 😅 I'll go read up on it and get back to you. 🫡 

#9

Technical support - Hardware related / Re: CPC 6128 - white screen, b...

Last post by McArti0 - Today at 13:26

Ok. Make OR Gate on breadbord. (From 2 NOR gate in 74Ls02).

#10

M

Technical support - Hardware related / Re: CPC 6128 - white screen, b...

Last post by mmldrm - Today at 12:23

Finally the 74LS02 has arrived!

I will try the above tests too, if I understand them. 

My oscilloscope is a Zoyi ZT-702S: https://zoyitools.com/product/zt-702s/

I found it for £43, and figured it's something I can use for years after this. This is true for the breadboard and components I bought for the tests - I like playing with electronics and would like to do more hardware projects in the future.

If these tests from @McArti0 can reduce the number of chips that I desolder and replace, I am less likely to destroy the motherboard in the process. Unorthodox, but I'm happy to proceed with caution on this.

Thanks for staying with me this far on the journey. I know there is a variety of opinions on the path we have taken.