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tms99xx: Fix some comments. (nw)

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Michael Zapf 2019-04-18 18:07:59 +02:00
parent dfbde43dda
commit 990e11598a
1 changed files with 12 additions and 7 deletions
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19
src/devices/cpu/tms9900/tms99com.h
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@ -13,11 +13,14 @@
TI990/12 Multi-chip implementation, faster than 990/10. Huge instruction set
TMS9900 Mono-chip implementation, 1976. Used in the TI-99/4(A) computer.
No mapper, no privileged mode.
TMS9940 Microcontroller with 2kb ROM, 128b RAM, decrementer, CRU bus, 1979
TMS9980 8-bit variant of tms9900. Two distinct chips actually : tms9980a
and tms9981 with an extra clock and simplified power supply
TMS9980 like TMS9900, but with integrated 16/8 databus multiplexer,
smaller address/cru space, and simplified interrupt input.
Two distinct chips actually: tms9980a, and tms9981 with an
extra clock and simplified power supply
TMS9985 9940 with 8kb ROM, 256b RAM, and a 8-bit external bus, c. 1978 (never released)
@ -25,8 +28,9 @@
SBP68689 Improved 9989, built as an ASIC as 9989 was running scarce
TMS9995 TMS9985-like, with many improvements (but no ROM). Used in the
TI-99/8 prototype and the Geneve computer.
TMS9995 TMS9985-like, with many improvements (but no ROM). Used in
some arcade systems, in the TI-99/2 and TI-99/8 prototype,
and in the Geneve computer.
TMS99000 Improved mono-chip implementation, meant to replace 990/10, 1981
TMS99105 This chip is available in several variants which are similar
@ -65,9 +69,10 @@ enum
};
/*
We are using setaddress this way: The address is the object to be
written; as address we use the values of the DBIN and IAQ lines. That
means we do not need separate dbin and iaq setting methods.
These values represent line states for bus control lines. In a setaddress
operation, the current state of the address bus lines is represented
by the address where these values are written to. The callee should check
the values to find out whether a read or write operation will follow.
*/
enum
{