🚀 go-pugleaf

In article <903@micomvax.UUCP> ray@micomvax.UUCP (Ray Dunn) writes:
>In article <3487@ihlpf.ATT.COM> nevin1@ihlpf.UUCP (00704A-Liber,N.) writes:
>> ....  About 7 years ago, I disassembled the BASIC ROMs on my TRS-80 Model I
>> I noticed a curious piece of code (which I will pseudocode here):
>>
[...]
>Without examining it too closely, it seems to me that it is MUCH more likely
>that you are disassembling on the wrong boundaries than the code is jumping
>into the middle of instructions!!  Interpreting binary dumps can be VERY
>misleading!

With all due respect, the TRS-80 *did* use this trick.  One instance was
the TRS-80 Basic SET and RESET instructions (which turned on/off a pixel
on the screen).  The SET instruction would have an entry point at 0200:
	0200  06 00	LD A,00
	0202  01 06 01	LD BC,0106	; this is just junk
	0205  ; real code starts here
and the RESET instruction would start at 0203:
	0203  06 01	LD A,01
	0205  ; real code starts here
[numbers are approximate]

Multiple entry points without the overhead of branches.
--
Felix Lee	flee@gondor.cs.psu.edu	*!psuvax1!gondor!flee