Recent posts

#1

Games / Re: Turrican (128K)

Last post by lightforce6128 - Today at 06:54

next week I'll try to write the changes in the Level A file, which should be very challenging.

Hopefully it will not be challenging. For compression you can use any language, and modern computers will process the data in any language (also slow scripting languages) more than fast enough.

Whenever you find a sequence of the same byte A of length N, replace it with these four bytes: A,N,#A5,#CC. Only apply this if the sequence is longer than 4 bytes. That's all. This is not the best compression, but a fast one that will work acceptably on sprites and level maps with much background.

Example:

"1,2,3,4,  a,a,a,a,a,a  ,5,6,7,8"  gets  "1,2,3,4,  a,6,#A5,#CC  ,5,6,7,8" (spaces only for better readability)

Hopefully the used escape sequence #A5,#CC is not used anywhere in the data to compress. If it is, either the escape sequence can be changed to something else, or it has to be encoded as sequence of length 1 (what will cost 3 bytes):

Example:
"1,2,3,  #A5,#CC  ,4,5,6"  gets  "1,2,3,  #A5,1,#A5,#CC,  #CC  ,4,5,6" (replace the #A5 with a sequence of length 1)


Two questions remain:

• Where should the file be loaded? Usually at the begin of the buffer that will contain the uncompressed data later.
• And which routine says the decompressor where the compressed data is located? Needed are begin and end of the data.

#2

Games / Re: retrosutra compares all AM...

Last post by Gryzor - Today at 05:48

Am interesting video nonetheless. I hadn't realized the Spectrum version looks so good and that the c64 version is so bad😁

[Retro Grade]

#3

C

Games / Re: Vespertino

Last post by cwpab - Today at 05:44

In 2025, some people still want to put cars and girls in the same "things to own, things to win in races" basket when official competitions are moving away from this.

Welcome the wrong side of retro, baby! Welcome... to the Retro Grade®.

[*throws himself to the highway and screams 'kill me, truck'*]

#4

C

Games / retrosutra compares all AMC ve...

Last post by cwpab - Today at 05:40

I wish this was intentional, it would be more like a conspiracy of sorts, more interesting to analyze.

Instead, it seems like the guy didn't realize! LOL, how can you NOT realize when the other 5 versions use the normal aspect ratio?

The reason why I believe it was accidental is because he refers to the CPC using words such as "the superior hardware of the CPC" and, in the end, he says he "personally prefer the Spectrum and Amstrad versions".

Ooops! I just spoiled the surprise... Yes, the only version with wrong aspect ratio is the Amstrad CPC one. *throws himself to the highway and screams 'kill me, truck'*

Here's the video:

#5

V

News & Events / TNMoC - Retro Jumble Sale

Last post by Vee - Yesterday at 22:55

Thought this may be interesting for some on the forum -

The National Museum of Computing at Bletchley Park (near Milton Keynes in the UK) is having a "Retro Jumble" sale.
"a fantastic selection of 1980s Retro PCs & Equipment on offer, featuring iconic brands like Amstrad, Commodore, and Dragon"

Details and tickets on the EventBrite page -
https://www.eventbrite.co.uk/e/retro-electro-jumble-tickets-1084147687919

#6

Classifieds / Re: [London] Looking to borrow...

Last post by Rabs - Yesterday at 21:55

I can buy one too (only the keyboard)!

What do you want 464, 6128? Message me.

#7

Programming / Re: Crash on a conversion from...

Last post by iXien - Yesterday at 21:52

Hi iXien,
The crack you are using doesn't use just files because it reads the data from sectors on the disk and the sectors are not data format.

Could you adapt the crack from Black Mission which just uses files?

Many thanks for this information. 

I suppose that it isn't possible to modify our current DSK so the game would be 100% standard files? We'll see if the BMC version can be patched. Hope this crack isn't too much compressed

#8

Amstrad CPC hardware / Re: Which chip for internal ro...

Last post by Rabs - Yesterday at 20:13

What about flash chips like  AT29C256 ? they are not easily sourced, but still a lot more recent than amstrad-period ROMs. They are 5v and the pinout seems ok... ?

I guess that's the problem, sourcing them.

#9

Classifieds / Re: [London] Looking to borrow...

Last post by m_dr_m - Yesterday at 18:19

I can buy one too (only the keyboard)!

#10

Classifieds / [London] Looking to borrow a C...

Last post by m_dr_m - Yesterday at 18:04

The CPC at my first isn't working properly (random crashes), and I need my daily dose!