bson@rice-chex.ai.mit.edu (Jan Brittenson) (11/20/90)
In Alonzo's HP28 Processor Notes, the section on the OUT instruction (in the table "by type") reads: Copy OUT register to register A or C 800 OUT.S C 801 OUT.X C Is 800 actually "OUT.X A" or should the description read "Copy register C to OUT register"?
akcs.joehorn@hpcvbbs.UUCP (Joseph K. Horn) (11/22/90)
Jan Brittenson asked: > In Alonzo's HP28 Processor Notes, the section on the OUT > instruction (in the table "by type") reads: > > > Copy OUT register to register A or C > > 800 OUT.S C > 801 OUT.X C > > Is 800 actually "OUT.X A" or should the description read > "Copy register C to OUT register"? Opcode 800 loads the least significant nib of OUT with the least significant nib of C. HP's mnemonic for this instruction is OUT=CS, where "S" stands for "Single nib", I suppose; it cannot stand for the S field, because OUT=CS copies nib 0, not nib F. Opcode 801 loads all three nibs of OUT with the three low-order nibs of C (not A), which is field X. HP's mnemonic for this instruction is OUT=C. There is an A=IN instruction, but no OUT=A (at least in the HP 71 and HP 28). This information is mere hearsay and not guaranteed blah blah. -- Joseph K. Horn -- (714) 858-0920 -- Peripheral Vision, Ltd.
bson@rice-chex.ai.mit.edu (Jan Brittenson) (11/23/90)
In article <274ae32a:1193.1comp.sys.handhelds;1@hpcvbbs.UUCP> akcs.joehorn@hpcvbbs.UUCP (Joseph K. Horn) writes: >> Copy OUT register to register A or C >> >> 800 OUT.S C >> 801 OUT.X C > Opcode 800 loads the least significant nib of OUT with the least > significant nib of C. So what we're looking at here, is actually OUT.1 C if I understand you correctly?
umapd51@cc.ic.ac.uk (W.A.C. Mier-Jedrzejowicz) (11/24/90)
The person who posted this question asks if the description of two machine language operations in Alonzo Gariepy's HP-28 Processor Notes is correct. If in doubt, go to the original sources, which Alonzo mentions - the HP-71B IDS, or if that is too expensive then my book "Customize Your HP-28". Both show that the opcodes 800 and 801 copy C(S) and C(X) respectively to the OUT register. Apologies to all readers to whom this is Greek (except the Greeks, to whom this is presumably Polish ;-) ). Oh, never mind. Unless you're Greek (or Polish - who are you voting for, in that case?) Wlodek Mier-Jedrzejowicz
alonzo@microsoft.UUCP (Alonzo GARIEPY) (11/29/90)
In article <11962@life.ai.mit.edu> bson@rice-chex.ai.mit.edu (Jan Brittenson) writes: > In Alonzo's HP28 Processor Notes, the section on the OUT instruction [reads]: > Copy OUT register to register A or C > 800 OUT.S C > 801 OUT.X C As you suggest, this is a typo and should properly read: Copy register C to OUT register 800 OUT.S C ; output sign field 801 OUT.X C ; output exponent field Thanks for pointing this out. Alonzo Gariepy alonzo@microsoft
akcs.joehorn@hpcvbbs.UUCP (Joseph K. Horn) (12/01/90)
Alonzo! Are you sure? The HP-71 Internal Design Specification says that opcode 800 loads the least significant nibble of the Output register with the LEAST SIGNIFICANT NIBBLE OF THE C REGISTER. That's _not_ the "sign field" nibble, which is the MOST significant nibble, right? HP's mnemonics call this nibble 0. The S field is nibble 15. -- Joseph K. Horn -- (714) 858-0920 -- Peripheral Vision, Ltd. --