maximal size of TRD image

Maximal size of TRD image - calculation:

- max. 16 sectors per track
- max. 256 tracks (0-255) per one disk side
- max. 2 disk sides

complette size:
16(sectors) x 256(tracks) x 2(sides) = 8192 sectors x 256 bytes(sector size) = 2048 kB = 2 MB.

Exist TRD creator(utility) with support this max. size limit ? :v2_conf3:
Can ZX emulators on PC work correct with bigger TRD images than 640kB ? :v2_eek:

I find on my HDD any TRD images with different length than 640kB (720kB and more < 640kB) :v2_conf2:

VELESOFT

Usually no.
Unreal ZX emulator can't use large (more than 83 tracks) trdos disk images - internal checking disable all tracks after 83 (even if it presents). And size of .TRD files can't be greater than 640K.
SCL files can contain more than 80-84 tracks, but you cant' is it because of track checking.

Supported both 640K images and cutted of .TRD files.
Cutted images does not contain zero-filled tracks at end of disk, at all.
I never (maybe I forgive it?) see .TRD images more than 640K.

Current utilities (AMD01, SpectrumNavigator, plugins for FAR) does not support larger than 640K size of .TRD files.

are you speaking about maximum capacity that TRD file format can provide?
yes, it may hold that much data, but this is incompatible with any ZX/TR-DOS emulators, since most capacious media supported by TR-DOS hardware/software is DS/DD floppies (standard capacity: 80tracks x 2sides x 16sectors x 256bytes = 640kB, max capacity: 86tracks x 2sides x 16sectors x 256bytes = 688kB)

This is TRD image created on SPECTRUM NAVIGATOR on PC (size 1MB = 128 tracks):
http://velesoft.speccy.cz/other/1mb_trd.zip :v2_jawdr:

And this is bigger TRD images finded on my HDD:
http://velesoft.speccy.cz/other/big_trd_images.zip :v2_conf2:

VELESOFT

it seems that these files (except for 240ds.trd which is simply broken) were made with PC software that doesn't care whether TRD images are valid.
none of ZX/TRDOS emulators can deal with extra space at the end of these images, though some of them may be able to handle first 640/688kB.

Цитата:

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Сообщение от GriV

Current utilities (AMD01, SpectrumNavigator, plugins for FAR) does not support larger than 640K size of .TRD files.

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after looking on xTRD 1.0 sources I see that it should support big .trd images. the plugin checks for tr-dos signature (0x10 at 0x08e7) and that file size is divisible by 16*256

at the same time it does not allow creation of images bigger that 640K

Цитата:

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Сообщение от VELESOFT

Maximal size of TRD image - calculation:

- max. 16 sectors per track
- max. 256 tracks (0-255) per one disk side
- max. 2 disk sides

complette size:
16(sectors) x 256(tracks) x 2(sides) = 8192 sectors x 256 bytes(sector size) = 2048 kB = 2 MB.

Exist TRD creator(utility) with support this max. size limit ? :v2_conf3:
Can ZX emulators on PC work correct with bigger TRD images than 640kB ? :v2_eek:

I find on my HDD any TRD images with different length than 640kB (720kB and more < 640kB) :v2_conf2:
VELESOFT

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в принципе возможно - пчему нет?
только, вроде, существующий спековский софт не поддержит дисков на 256 дорожек, максимум - 128, птому как, если склероз не подводит, под сторону и номер дорожки обычно отводится один байт.
могу и ошибаться.

вроде, даже при записи дальше 128 дорожки косяк будет, просто потому, что в каталоге под дорожку/сторону тож один байт...

Цитата:

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Сообщение от Antipod

в принципе возможно - пчему нет?
только, вроде, существующий спековский софт не поддержит дисков на 256 дорожек, максимум - 128, птому как, если склероз не подводит, под сторону и номер дорожки обычно отводится один байт.
могу и ошибаться.

вроде, даже при записи дальше 128 дорожки косяк будет, просто потому, что в каталоге под дорожку/сторону тож один байт...

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Yes, thank. One byte = 256 x 16sectors(4kB) = 1024kB=1MB.
Only FDC controller(VG93) can use 256(tracks) x 2(sides) x16sectors(track size for trdos) = 256x2x4kB = 2MB disk image(but only first 1MB is usable in TRDOS).

VELESOFT