Atari 130XE Uživatelský manuál stáhnout pdf (Strana 47)

7 Programming the ﬂash ROM

7.1 Basics

The software of the

TURBO FREEZERs

is not, as this is normally the case, stored in

an EPROM but in a ﬂash ROM. The big advantage of the ﬂash ROM is that it can be

re-programmed directly via the Atari. This means software updates can be installed at any

time and the unused parts of the ﬂash ROM can be ﬁlled with module data without the

need for a special programming device. The ﬂash ROM in the

TURBO FREEZER

can

be re-programmed up to 1.000.000 times, which should be enough for most experiments.

The ﬂash ROM and the freezer RAM of the

TURBO FREEZER

are normally protected

against overwriting. The “

FlashWrite

” must be moved to the right position (

) to enable

write access to both memories. If the switch is in the left position (

OFF

), the ﬂash ROM

and the freezer RAM are write protected. It is very unlikely that any software overwrites

the ﬂash ROM accidentally. To program the ﬂash ROM a special write sequence must be

sent to the ﬂash ROM, otherwise write access is simply ignored. Therefore is not really

dangerous to have the “FlashWrite” switch in the right position (ON) permanently.

When using “real” bank switching cartridges in the cartridge port both the

“

CartEmu

” as well as the “

FlashWrite

” switch should be turned

OFF

. This prevents a

conﬂict between the cartridge emulation and the bank switching cartridges.

Caution:

It is important that the “

OldOS

” switch is turned

OFF

during ﬂashing in

order to ensure that the ﬂash ROM is exclusively accessible by the ﬂashing program. If

the Oldrunner is active at the same time conﬂicts can occur –

e. g.

when an interrupt is

raised – and the Atari can crash.

7.2 Banks and blocks in the ﬂash ROM

It is helpful to know some details about the inner structure of the ﬂash ROM in order

to use it best. The used ﬂash ROM is partitioned into blocks of 64k each (

i. e.

eight 8k

banks). These blocks can be re-programed completely independent of each other. This

means that

e. g.

changes to the data of the cartridge emulation to not impact the freezer

software and vice versa.

Unfortunately the partitioning into 64k blocks also has a small disadvantage. It is not

possible to re-program only a part of a 64k block. Still free, not yet programmed parts can

be programmed later on. You can for example ﬁrst program an 8k module into bank 0 and

program later another 8k module into bank 1 of the same block. But is it recommended

to merge several

e. g.

8k modules into a large ﬁle and program them then in one go. The

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