Imaging - Compression error (-2)

Discuss ADFFS development and download test releases
Post Reply
timw
Posts: 3
Joined: Tue Jul 27, 2021 10:23 pm

Imaging - Compression error (-2)

Post by timw »

Hi Jon, firstly thanks for creating ADFFS and the whole preservation initiative, it's really great and much appreciated!

I'm trying to make a JFD image of Chocks Away Mark II disc 1, and I'm getting "Compression error (-2)" towards the end of the process. This is with my own recording file (I think my discs have some additional files saved on them). I was able to image Saloon Cars discs 1 and 2 successfully, so in general it works on my machine. I saw that in the past this error occurred when using the ROL version of ZLib, but I don't have this so it's using the ZLib module provided with ADFFS. This is with ADFFS version 2.73 on a 4MB A3000, ARM2, RISC OS 3, ZIDEFS hard disc.

I don't have anything installed on the machine so there's no nested wimp or whatever it is that is needed to populate the imaging menu with the titles, so I edited the DATA statements so that I only get offered the one title that I'm going to image and that seems to work OK. By the way, there is a small bug if you try to image without populating the data - the program tries to read nonexisting system variables and the call to PROCerror fails because the parameters are wrong (I guess it's left over from an earlier version).

Any ideas about the ZLib error? Thanks!

timw
Posts: 3
Joined: Tue Jul 27, 2021 10:23 pm

Re: Imaging - Compression error (-2)

Post by timw »

I've just tried it with the standard 800k recording file and it worked fine... then again with my original recording file (761 sectors), and it also worked fine! So I don't know why it repeatedly failed the first time I tried. The only difference is that then I had an 840 ish kB RAM disc, apart from this it was a clean boot.

JonAbbott
Posts: 2446
Joined: Thu Apr 11, 2013 12:13 pm
Location: Essex
Contact:

Re: Imaging - Compression error (-2)

Post by JonAbbott »

ZLib doesn't provide very useful error messages, but I'm guessing it couldn't allocate RMA space to perform the compression. From memory, I think it needs around 64KB of RMA free.
timw wrote:
Wed Jul 28, 2021 10:58 pm
I don't have anything installed on the machine so there's no nested wimp or whatever it is that is needed to populate the imaging menu with the titles, so I edited the DATA statements so that I only get offered the one title that I'm going to image and that seems to work OK.
You just need a bare !Boot with a recent Wimp Module
timw wrote:
Wed Jul 28, 2021 10:58 pm
By the way, there is a small bug if you try to image without populating the data - the program tries to read nonexisting system variables and the call to PROCerror fails because the parameters are wrong
Thanks, I'll modify the metadata side so it doesn't let you start imaging unless you've filled in the bare minimum of fields.

timw
Posts: 3
Joined: Tue Jul 27, 2021 10:23 pm

Re: Imaging - Compression error (-2)

Post by timw »

Thanks, that's probably the reason, as memory was a bit tight with the RAM disc allocated.

I realised I have another version of Chocks Away Mark II (not Extra Missions). It's on a single E format disc, has different icon sprites from the original and no protection, and can be dragged across to hard disc and run from there alone (the references to adfs::0 have been replaced with <Chocks$Dir>). There are no obvious gameplay changes from the 2 disc version. It's dated 1993 and I think it came with a subscription to Acorn User or something like that. It came with a printed manual (same content as original, but not on shiny paper) and no box. I wonder what the distribution rights are for this version.

Post Reply