CP/M/CPM_CDROM.iso/simtel/sigm/vols000/vol087/modem.hlp

Text File | 1985-02-10 | 17.5 KB | 407 lines

INTRODUCTION to Communications Utilities
The "MODEM" family of programs
The "YAM" family of programs
Gettinτ "YAM/MODEMó t∩ you≥ compute≥
YAMBOOT details
MBOOT details
The YAM/MODEM Handshake Protocol
Other programs which WILL work with YAM/MODEM
Other programs which MAY work with YAM/MODEM
Preconfigured versions of YAM/MODEM7 for specific computers
XYAM and XMODEM
XSTAM details
XSTAM caveats
Using CRCK to check file transfers
:Introduction

Thσá concep⌠á oµá Remotσ CP/═ (RCPM⌐ system≤ relie≤á oεá user≤ ì
havinτ thσ abilit∙ t∩ transfe≥ file≤ t∩ anΣ froφ thσ systeφ iε ì
somσá securσá manner«á Thσá securit∙á come≤á froφá handshakinτ ì
betweeεá thσ sende≥ anΣ receive≥ t∩ le⌠ thσ sende≥á kno≈á tha⌠ ì
thσ receive≥ go⌠ ß gooΣ (n∩ errors⌐ cop∙ oµ thσ file.

T∩á datσ therσ ha≤ beeε littlσ neeΣ fo≥ thesσ typσ oµ program≤ ì
iεá Australißá a≤ microcompute≥ user≤ havσ no⌠á beeεá strongl∙ ì
communication≤ oriented¼ mostl∙ duσ t∩ restrictivσ policie≤ oε ì
thσ par⌠ oµ Telecom«á Wha⌠ littlσ neeΣ therσ ha≤ beeε ha≤ beeε ì
met¼á iε thσ CP/═ environmen⌠ a⌠ least¼ b∙ commercia∞ program≤ ì
sucΦ a≤ BSTAM«

Wha⌠á i≤á requireΣ fo≥ interactivσ communicatioε witΦá ßá RCP═ ì
systeφá i≤ utilit∙ whicΦ wil∞ allo≈ ASCI╔á communication≤á fo≥ ì
logiεá anΣá RCP═á commanΣá instigatioεá anΣá wil∞á als∩á allo≈ ì
handshakinτá (o≥á protocol⌐ filσ transfer≤ iε botΦá direction≤ ì
withou⌠á havinτá t∩á returε t∩ thσá operatinτá systeφá commanΣ ì
level.


Iε thσ USA¼á RCP═ system≤ havσ beeε oε linσ fo≥ severa∞á year≤ ì
anΣ severa∞ program≤ whicΦ fulfil∞ thσ abovσ requirement≤ havσ ì
beeε developed« Thesσ havσ developeΣ iε tw∩ streams.

Thσ firs⌠ streaφ i≤ thσ serie≤ oµ program≤ whicΦ g∩ unde≥á thσ ì
generiπá titlσá oµá "MODEM"«á Thesσ program≤ al∞ steφá froφá ß ì
prograφá writteε b∙ WarΣ Christenseε iε Chicag∩ fo≥á thσá ver∙ ì
firs⌠á RCP═á systeφá calleΣá CBB╙á (actuall∙á thσá ver∙á firs⌠ ì
microcompute≥á bulletiε boarΣ systeφ iε thσ world)«á Thσ MODE═ ì
program≤ arσ al∞ writteε iε 808░ assembl∙ codσ anΣ arσ iεá thσ ì
publiπ domain.

Thσá seconΣ streaφ i≤ ß serie≤ oµ program≤ whicΦ g∩ unde≥á thσ ì
namσ oµ YA═ ("Y"e⌠ "A"nothe≥ "Modemó program)«á Thesσ program≤ ì
steφá froφ attempt≤ t∩ rewritσ thσ MODE═ program≤ int∩ thσ "Có ì
higΦ leve∞ language« Thσ YA═ programs¼ b∙ Chucδ Forsberg¼ gre≈ ì
froφá thσ MODEM.├ programs«á YA═ offer≤ man∙á morσá facilitie≤ ì
thaεá MODE═á anΣ i≤ easie≥ t∩ maintain«á YA═ program≤ usσá thσ ìèsamσá protocol≤ a≤ thσ MODE═ program≤ anΣ the∙ wil∞ "talkóá t∩ ì
eacΦ other.

:The "MODEM" family of programs

Thσá "MODEMó famil∙ oµ program≤ arσ writteε iεá 808░á assembl∙ ì
languagσáá anΣá arσá probabl∙á no⌠á portablσá t∩á non-8080/Z8░ ì
environment≤ withou⌠ ß grea⌠ dea∞ oµ work.

Thσá program≤á arσ writteε arounΣ PMM╔ anΣá D.C«á Haye≤á S-10░ ì
modeφ cards¼á thesσ card≤ arσ BEL╠ 10│ standarΣ modem≤ anΣ arσ ì
quitσá useles≤á iε Australia«á Thσ program≤ suppor⌠á autodial¼ ì
auto-answe≥á anΣ callbacδ facilitie≤ whicΦ arσá generall∙á no⌠ ì
applicablσá t∩ thσ externa∞ modem≤ anΣ acoustiπ coupler≤á useΣ ì
iε Australia« Thσ program≤ caε bσ modifieΣ with¼ somσ care¼ t∩ ì
ruε successfull∙ witΦ externa∞ modems/couplers.

Yo⌡á canno⌠ assemblσ thσ MODE═ program≤ witΦ thσ standarΣ CP/═ ì
assembler¼á ASM.COM«á Thσá Digita∞á ResearcΦá macr∩á assemble≥ ì
MAC.CO═ i≤ required¼á thougΦ yo⌡ coulΣ probabl∙ ge⌠ awa∙á witΦ ì
thσá Microsof⌠ M80.CO═ assemble≥ provideΣ yo⌡ werσ prepareΣ t∩ ì
d∩ ß bi⌠ morσ editinτ oµ thσ sourcσ files«á WitΦ haΣ expansioε ì
oµ thσ macro≤ i⌠ jus⌠ ma∙ bσ possiblσ t∩ usσ ASM.COM.



Iµá yo⌡ arσ comfortablσ witΦ 808░ assemble≥ codσ anΣ kno≈á thσ ì
technica∞ detail≤ oµ thσ UAR╘ whicΦ drive≤ you≥á modem/couple≥ ì
yo⌡ shoulΣ bσ ablσ t∩ modif∙ MODE═ t∩ sui⌠ you≥ needs.

Thσá versioεá oµ MODE═ currentl∙ availablσ oε thi≤á systeφá i≤ ì
calleΣáá MODEM7«áá Seσá thσá filσá MODEM7.DO├á fo≥á thσáá ful∞ ì
documentatioε oε thσ program.

:The "YAM" family of programs

YA═ i≤ writteε iε ß modern¼á higΦ leve∞ language¼á "C"« I⌠ wa≤ ì
writteεá witΦ thσ ideß tha⌠ i⌠ shoulΣ bσ transportablσ t∩ non-ì
CP/═á environment≤á anΣá i≤ thσ onl∙ choicσá iµá yo⌡á arσá no⌠ ì
runninτ aε 8080/Z8░ processor.

Thσá prograφá i≤ writteε iε ß modula≥ manne≥ anΣ al∞ thσá UAR╘ ì
dependen⌠á routine≤á arσ containeΣ iε ßá singlσá module«á Somσ ì
othe≥á hardwarσ dependen⌠ informatioε (sucΦ a≤ por⌠á addresse≤ ì
etc⌐á i≤á containeΣá iε heade≥ files«á Thi≤ makσá i⌠á eas∙á t∩ ì
suppor⌠á multiplσ version≤ oµ YA═ froφ substantiall∙ thσá samσ ì
se⌠á oµ files«á Thσ SYSO╨ i≤ currentl∙ supportinτ │á differen⌠ ì
UAR╘ version≤ oµ YA═ froφ thσ onσ se⌠ oµ sourcσ files.






è

Yo⌡ wil∞ neeΣ t∩ thσ BD╙ "Có compiler¼á versioε 1.4▒ o≥ later¼ ì
t∩á compilσ YAM«á Iµ yo⌡ havσ ß versioε earlie≥ thaε 1.4╢á (o≥ ì
perhap≤ 1.45a⌐ yo⌡ ma∙ als∩ neeΣ thσ MA├ assemble≥ iµ yo⌡ wan⌠ ì
t∩á modif∙á thσ tw∩ assemble≥ module≤ YAM╕ anΣá YAM9«á Iεá thσ ì
norma∞á coursσá oµá event≤ yo⌡ wil∞ no⌠ neeΣá t∩á toucΦá thesσ ì
modules¼á thσ preassembleΣ CR╠ file≤ fo≥ thesσ tw∩ module≤ arσ ì
availablσá fo≥ downloadinτ froφ thi≤ system«á Version≤ oµá thσ ì
BD╙á "Cóá compile≥ froφ 1.4╢ onwarΣ allo≈ thσ usσá oµá AS═á t∩ ì
producσá CR╠á files¼á bu⌠á yo⌡ woulΣ theε neeΣ t∩á modif∙á thσ ì
YAM8/9.AS═ module≤ t∩ sui⌠ thσ ne≈ method.

Iµá yo⌡á arσá comfortablσ witΦ thσá "Cóá languagσá yo⌡á shoulΣ ì
definitel∙á usσá YA═á insteaΣ oµ MODEM«á Eveε iµ yo⌡á arσá no⌠ ì
familia≥á witΦ "Có i⌠ i≤ wortΦ thσ effor⌠ oµ learning¼á t∩á bσ ì
ablσ t∩ compilσ YAM«á YA═ i≤ ß mucΦ morσ flexiblσ utilit∙ thaε ì
MODE═á anΣá i≤á typica∞ oµ thσ numerou≤á higΦá qualit∙á publiπ ì
domaiε utilitie≤ availablσ iε "C".

Thσá versioε oµ YA═ currentl∙ availablσ oε thi≤ systeφ i≤á YA═ ì
3.09«á Seσá thσá filσ YAM.DO├ fo≥ ful∞á documentatioεá oεá thσ ì
program. (Unix users ask the SYSOP about UMODEM27.C)

:Getting "YAM/MODEM" to your computer

Unti∞ yo⌡ havσ ß cop∙ oµ YA═ o≥ MODE═ thσ onl∙ wa∙ t∩ transfe≥ ì
datßá i≤á a≤á ASCI╔á text«á BotΦ YA═ anΣ MODE═á arσá botΦá biτ ì
program≤á anΣá thσá chance≤á oµ transferrinτá theφá vißá phonσ ì
withou⌠ somσ error≤ arσ no⌠ good.

Thσ solutioε i≤ t∩ usσ eithe≥ oµ thσ shor⌠ program≤á YAMBOOT.├ ì
o≥á MBOOT.ASM«á YAMBOO╘ i≤ ß minima∞ versioε oµ YA═ (wel∞ sor⌠ ì
of⌐  anΣ MBOO╘ i≤ ß minima∞ versioε oµ MODE═ «á Virtuall∙á al∞ ì
the∙ caε d∩ i≤ receivσ file≤ usinτ thσ "Christensenó protocol« ì
Thσá basiπá ideß i≤ tha⌠ yo⌡ transfe≥ YAMBOOT.├ o≥á MBOOT.ASM¼ ì
whicΦá arσ relativel∙ short¼á t∩ you≥ systeφ a≤ ASCI╔ tex⌠á b∙ ì
typinτá thσá file«á (Seσ thσ "YAMBOO╘á detailsóá categor∙á fo≥ ì
details)«áá Yo⌡á theεá compile/assemblσá YAMBOOT/MBOOT¼áá witΦ ì
appropriatσ UAR╘ datß fo≥ you≥ system¼á anΣ usσ i⌠ t∩ transfe≥ ì
YA═ o≥ MODE═ witΦ thσ securit∙ oµ ß protoco∞ transfer.

Theεá yo⌡ compile/assemblσ thσ YAM/MODE═ sourcσ codσ witΦá fo≥ ì
you≥ computer.

:YAMBOOT details

Therσá i≤á ßá prograφ calleΣ YAMBOOT.├ oεá thi≤á system«á Thi≤ ì
prograφá i≤ thσ madσ u≡ froφ part≤ oµ thσ YA═ prograφ bu⌠á ha≤ ì
n∩ 'frills'.

Iµá yo⌡á havσ somσ wa∙ t∩ prin⌠ you≥ dialoτ witΦá thi≤á systeφ ì
theε TYP┼ thσ file¼á anΣ prin⌠ i⌠ t∩ you≥ printer«á YAMBOO╘ i≤ ì
theε smal∞ enougΦ t∩ typσ int∩ you≥ systeφ anΣ compile.
èAlternativel∙á iµ yo⌡ havσ aε ASCI╔ transfe≥ prograφá sucΦá a≤ ì
BSTM╙ o≥ TELNET¼ whicΦ allow≤ yo⌡ t∩ capturσ ASCI╔ tex⌠ froφ ß ì
remotσ system¼á yo⌡ caε savσ thσ YAMBOO╘ sourcσ tex⌠ a≤ ß filσ ì
anΣ avoiΣ thσ retypinτ beforσ compilinτ it«

Wheεá YAMBOO╘ ha≤ beeε compileΣ yo⌡ caε down-loaΣ thσ ful∞ YA═ ì
o≥ MODEM╖ program.

Seσá thσ READ-ME.YA═ filσ anΣ YAMBOOT.├ itselµ fo≥ detail≤á oµ ì
wha⌠ yo⌡ neeΣ t∩ kno≈ t∩ compilσ YAMBOOT.



YAMBOO╘ i≤ thσ MUC╚ easie≥ t∩ ge⌠ goinτ thaε MBOO╘ iµ yo⌡ havσ ì
thσ BD╙ "Có compiler« Yo⌡ onl∙ neeΣ t∩ havσ you≥ BDSCIO.╚ filσ ì
se⌠á u≡ correctl∙ fo≥ you≥ modeφ por⌠ (whicΦ i≤ obviousl∙á thσ ì
casσá iµá yo⌡ arσ usinτ TELNET)«á Theε yo⌡ shoulΣ bσá ablσá t∩ ì
compilσ YAMBOO╘ withou⌠ an∙ change≤ a⌠ all.

:MBOOT details

Yo⌡á wil∞ neeΣ t∩ havσ reaΣ thσ precedinτá categor∙á YAMBOOT.├ ì
beforσ readinτ thi≤ one.

Dowεáá loaΣá MBOO╘á a≤á outlineΣá fo≥á YAMBOO╘á anΣá pu⌠áá thσ ì
appropriatσ UAR╘ datß fo≥ you≥ modeφ por⌠ int∩ it«á Notσá tha⌠ ì
MBOOT.AS═á ha≤ haΣ severa∞ spacσ savinτ trick≤ applieΣ t∩á it¼ ì
t∩á minimizσ it≤ sizσ anΣ transmissioε time«á I⌠ ma∙ no⌠á looδ ì
likσá thσá assemble≥ codσ tha⌠ yo⌡ arσ useΣ t∩ seeinτá bu⌠á i⌠ ì
wil∞ assemblσ OK«

Wheεá MBOO╘ ha≤ beeε assembleΣ yo⌡ caε dowε loaΣ thσ ful∞á YA═ ì
o≥ MODEM╖ program.

MBOO╘ wil∞ onl∙ worδ witΦ Z8░ o≥ 808░ CPUs«á Remembe≥ yo⌡ neeΣ ì
t∩á havσ patcheΣ int∩ i⌠ thσ statu≤ anΣ datß por⌠á informatioε ì
relevan⌠ t∩ you≥ seria∞ I/╧ board.

:The YAM/MODEM Handshake Protocol

BotΦá YA═á anΣá MODE═á usσ thσá samσá handshakσá protoco∞á fo≥ ì
transferrinτá singlσ file≤ anΣ caε worδ witΦ eacΦ other«á The∙ ì
usσ ß differen⌠ protoco∞ iε thσ "batchó modσ anΣ wil∞ NO╘ worδ ì
witΦ eacΦ othe≥ iε thi≤ mode«á BotΦ YA═ anΣ MODE═ usσ thσ samσ ì
CR├á checδ wheε runninτ iε tha⌠ modσ anΣ wil∞ worδá witΦá eacΦ ì
othe≥ fo≥ singlσ filσ transfers.

Thσ "Christensenó protoco∞ useΣ b∙ YA═ anΣ MODE═ i≤á describeΣ ì
iε thσ filσ PROTOCOL.DOC.

T∩á determinσ thσ difference≤ iε thσ batcΦ modσ protocol≤á seσ ì
thσ file≤ YAM.DO├ anΣ MODEM7.DOC.

:Other programs which WILL work with YAM/MODEM
èListeΣá belo≈á arσ othe≥ program≤ whicΦ thσ SYSO╨á know≤á wil∞ ì
worδ witΦ YA═ o≥ MODEM7«á Iµ yo⌡ kno≈ oµ other≤ pleasσ leavσ ß ì
messagσ fo≥ thσ SYSOP.

"RCPMLINK.COM" fo≥ thσ Osbornσ ▒ compute≥.
ì
Thi≤á prograφ use≤ thσ "Christensenó protocol≤ anΣ i≤á claimeΣ ì
t∩á bσá full∙ compatiblσ witΦ MODEM«á Thσ SYSO╨ ha≤ testeΣá i⌠ ì
witΦ YA═ anΣ successfull∙ transferreΣ file≤ iε botΦ direction≤ ì
iεá thσá singlσ filσ mode«á RCPMLIN╦ i≤ ßá commercia∞á prograφ ì
baseΣ oε MODEM«

"CMODEM.├"

Thi≤ prograφ i≤ froφ thσ "CNODEó RCP═ systeφ iε thσ US┴ anΣ i≤ ì
writteεá iε BD╙ "C"«á ╔ havσ testeΣ i⌠ witΦ XYA═ anΣ i⌠á work≤ ì
fine« I⌠ i≤ aε enhanceΣ versioε oµ YAMBOO╘ anΣ wil∞ senΣ file≤ ì
a≤á wel∞á a≤ receivσ them¼á bu⌠ i≤ reall∙ onl∙ ß ver∙á minima∞ ì
communication≤ utility«


Sincσ thσ ful∞ YA═ sourcσ i≤ availablσ oε thi≤ system¼á anΣ i⌠ ì
offer≤á many¼á man∙ morσ facilitie≤ thaε CMODEM¼á therσá seem≤ ì
littlσá poin⌠á iε usinτ CMODEM«á Howeve≥ iµ yo⌡á havσá unusua∞ ì
hardwarσá anΣ finΣ i⌠ difficul⌠ t∩ ge⌠ YA═ goinτ CMODE═á woulΣ ì
probabl∙ bσ ß easie≥ t∩ adapt«á I⌠ shoulΣ certainl∙ ruε oε an∙ ì
systeφ tha⌠ caε ruε TELNET«á  Alternativel∙ iµ yo⌡ havσ ßá lo≈ ì
capacit∙á disδ systeφ o≥ arσ shor⌠ oµ memor∙ thσ smalle≥á sizσ ì
oµ CMODE═ ma∙ bσ attractivσ t∩ you«á Seσ thσ star⌠ oµ CMODEM.├ ì
fo≥ documentation.

:Other programs which MAY work with YAM/MODEM

ListeΣá belo≈ arσ othe≥ program≤ whicΦ thσ SYSO╨ suspect≤á ma∙ ì
worδá witΦ YA═ o≥ MODEM7«á Thesσ program≤ havσ NO╘ beeε testeΣ ì
anΣ thσ SYSO╨ woulΣ appreciatσ an∙ furthe≥ information.


UMODEM27

Thi≤ prograφ i≤ writteε iε "Có fo≥ Uni° systems« I⌠ implement≤ ì
thσ "Christensenó protocol≤ anΣ shoulΣ bσ compatiblσ witΦá YA═ ì
and MODEM7. All I need is some Unix user to try it out.


M.I.T.E.

No⌠á t∩á bσá confuseΣ witΦ HITE«á Thi≤ CP/═á prograφá i≤á froφ ì
Mycrof⌠á Lab≤ iε thσ U.S.A«á anΣ i≤ supposeΣ t∩ implemen⌠á thσ ì
"Christensenó protocols« I'vσ neve≥ eveε seeε ß copy.

:Preconfigured version of YAM/MODEM7 for specific systems

WitΦ reasonablσ skill¼á thσ "standardó version≤ oµ YAM/YAMBOO╘ ì
anΣá MODEM7/MBOO╘ shoulΣ bσ ablσ t∩ bσ implementeΣ oε an∙ CP/═ ìèsystem«á Howeve≥á duσá t∩á thσá non-standarΣá naturσá oµá somσ ì
systems¼ particularl∙ system≤ no⌠ originall∙ intendeΣ fo≥ CP/═ ì
operatioε sucΦ a≤ thσ Applσ 2¼á ß preconfigureΣ versioε oµ thσ ì
communications utilities may be on line for down loading.

Thσá onl∙á preconfigureΣá versioεá kep⌠ oε linσá arσá fo≥á thσ ì
popula≥áá machines¼áá i.σá Apple¼áá Sorcere≥áá etc«áá bu⌠áá iµ ì
version≤á fo≥á othe≥ machine≤ arσ availablσ therσá wil∞á bσá ß ì
documen⌠á filσ oε thσ A║á o≥ B║á drive¼á  whicΦ wil∞ a⌠á leas⌠ ì
mentioε thσ availability¼ b∙ request, oµ othe≥ versions.

Thesσ preconfigureΣ version≤ havσ beeε contributeΣ b∙ use≤ wh∩ ì
haΣ t∩ develo≡ theφ thσ "hardó way« Iµ yo⌡ d∩ ß ne≈ versioε oµ ì
thσ communication≤ utilitie≤ fo≥ you≥ systeφ pleasσ contributσ ì
you≥á versioε s∩ tha⌠ othe≥ user≤ oµ you≥ typσ oµá systeφá caε ì
benefi⌠ froφ you≥ efforts.

:XYAM and XMODEM

XYA═á anΣ XMODE═ arσ specia∞ version≤ YA═ anΣ MODEM«á The∙ arσ ì
designeΣ fo≥ usσ oε RCP═ system≤ anΣ a≤ sucΦ havσ somσ specia∞ ì
feature≤ necessar∙ iε tha⌠ sor⌠ oµ environment.

Generall∙á thesσ feature≤ arσ designeΣ t∩ makσ theφá eas∙á fo≥ ì
thσ remotσ use≥ t∩ contro∞ (i.e« morσ messages⌐ anΣ t∩ preven⌠ ì
"dangerousóá thing≤á happeninτ t∩ thσ RCP═á systeφá (i.e«á CO═ ì
file≤á beinτá sen⌠ t∩ thσ RCP═ systeφ anΣ theε beinτá useΣá t∩ ì
crasΦ thσ system)«

Oεá an∙á RCP═ systeφ therσ arσ certaiε systeφ file≤ whicΦá arσ ì
no⌠á availablσ fo≥ transfe≥ (fo≥ ß variet∙á oµá reasons)«á Thσ ì
XYAM/XMODE═á program≤á caεá detec⌠ thesσ file≤á anΣá wil∞á no⌠ ì
transfe≥ them.

Thσá prograφá useΣá oε thi≤ systeφ i≤ XYAM«áì

:XSTAM details

XSTA═á i≤á ßá BSTA═á compatiblσ utility«á BSTA═á i≤á fa≥á froφ ì
satisfactor∙ fo≥ usσ oε aε RCP═ system« I⌠ i≤ difficul⌠ t∩ le⌠ ì
thσá remotσ user≤ WH┘ ß transfe≥ operatioε wa≤ no⌠á successfu∞ ì
anΣá i⌠ i≤ impossiblσ t∩ abor⌠ thσ senΣ enΣ froφá thσá receivσ ì
end«á BSTAM/HITE/XSTA═ havσ t∩ bσ ruε a≤ stanΣ alonσ programs¼ ì
the∙á havσá n∩ ASCI╔ communication≤ capabilit∙ anΣá thi≤á als∩ ì
make≤ theφ mucΦ morσ cumbersomσ t∩ use.

Howeve≥á quitσ ß fe≈ user≤ seeφ t∩ alread∙ havσ BSTA═ o≥á HIT┼ ì
s∩á thσ XSTA═ utilit∙ i≤ provideΣ fo≥ thesσ users«á Yo⌡ reall∙ ì
shoulΣá onl∙á usσ XSTA═ t∩ ge⌠ dowε loaΣ YA═ o≥á MODEM╖á iεá ß ì
securσá manne≥ anΣ theε ge⌠ YA═ o≥ MODEM╖ runninτ a≤ thesσ arσ ì
fa≥ superio≥ utilitie≤ iε ever∙ respect.

Notσá tha⌠á XSTA═á wil∞ no⌠ transmi⌠ file≤ tha⌠á wil∞á no⌠á bσ ì
transmitteΣ b∙ XYA═ (seσ previou≤ categor∙ fo≥ detail≤ oµá thσ ì
restriction≤á XYA═ applies)«á However¼á unlikσ YA═ o≥á MODEM7¼ ìètherσá i≤ n∩ wa∙ fo≥ XSTA═ t∩ tel∞ yo⌡ wha⌠ happened¼á i⌠ wil∞ ì
simpl∙ thinδ tha⌠ yo⌡ didn'⌠ specif∙ an∙ filσ fo≥ transmissioε ì
iµ yo⌡ specif∙ ß restricteΣ file.
:XSTAM caveats

"XSTAM.COMóá work≤ exactl∙ likσ BSTA═á "TRANSMIT.COM"¼á excep⌠ ì
tha⌠á i⌠á i≤á les≤á verbosσá a≤ fa≥á a≤á thσá remotσá use≥á i≤ ì
concerned«á Yo⌡á wil∞á neeΣ t∩ star⌠ thσ utilit∙ oεá thσá RCP═ ì
systeφá firs⌠ anΣ theε exi⌠ froφ you≥á communication≤á prograφ ì
anΣ star⌠ thσ appropriatσ BSTA═ o≥ HIT┼ utilit∙ a⌠ you≥ end.

XSTA═á shoulΣá alway≤á abor⌠ a⌠ thσ RCP═ enΣ iµ therσá arσá 2░ ì
erro≥ message≤ oµ an∙ typσ (eithe≥ beforσ transmissioεá start≤ ì
o≥á betweeε successfull∙ transmitteΣ blocks⌐ displayeΣ a⌠á thσ ì
RCP═ end«á Ver∙ fe≈ message≤ froφ XSTA═ arσ sen⌠ t∩ thσ remotσ ì
user¼á howeve≥á the∙ d∩ stil∞ displa∙ oε thσ RCP═ console«á Iµ ì
yo⌡á ge⌠ continua∞ "TIM┼ OU╘ ERRORSó a⌠ you≥á end¼á XSTA═á ha≤ ì
probabl∙ aborted.

Iµ therσ arσ ß relativel∙ smal∞ numbe≥ oµ carrie≥ losse≤ (>10⌐ ì
XSTA═á wil∞á abor⌠á anΣá iµ carrie≥ i≤ los⌠ fo≥á morσá thaεá ╡ ì
second≤ XSTA═ wil∞ abort« Yo⌡ shoulΣ definitel∙ no⌠ tr∙ t∩ usσ ì
XSTA═á iµá thσá RCP═á systeφ ha≤á troublσá holdinτá ont∩á you≥ ì
carrier«á Thesσ carrie≥ los≤ abor⌠ measure≤ arσ necessar∙á duσ ì
t∩á thσá desigεá oµ BSTAM¼á whicΦ reall∙ expect≤á t∩á havσá aε ì
operato≥ a⌠ eacΦ end.


Iε mos⌠ case≤ XSTA═ wil∞ returε yo⌡ t∩ CP/═ commanΣ leve∞ wheε ì
i⌠á abort≤á bu⌠á thσ communication≤ superviso≥ ma∙á decidσá t∩ ì
terminatσá thσá cal∞á iµ thσ XSTA═ abor⌠ wa≤á duσá t∩á carrie≥ ì
losse≤á ("HEL╨á THIS-SYSó give≤ detail≤ oµá thσá circumstance≤ ì
unde≥á whicΦá thσá communication≤á superviso≥á ma∙áá terminatσ ì
calls).

Iµ yo⌡ havσ BSTA═ o≥ HIT┼ ╔ expec⌠ tha⌠ yo⌡ kno≈ ho≈ t∩ usσ i⌠ ì
correctly«á ╔á wil∞á no⌠á providσá assistancσá t∩á user≤á witΦ ì
BSTAM/HIT┼á problem≤ unles≤ the∙ caε bσ clearl∙ traceΣ t∩á thσ ì
RCP═á end«á D∩ no⌠ expec⌠ XSTA═ t∩ bσ alway≤ availablσ oε thi≤ ì
system«á A≤ thσ numbe≥ oµ YAM/MODEM╖ user≤ increase≤ XSTA═ anΣ ì
implementation≤á fo≥á thσ morσ commoεá computer≤á arσá readil∙ ì
available¼ XSTA═ wil∞ probabl∙ bσ withdrawn.

Iµ yo⌡ havσ BSTA═ o≥ HIT┼ yo⌡ shoulΣ definitel∙ usσ i⌠ t∩ dowε ì
loaΣá YA═á o≥á MODEM7¼á insteaΣ oµ thσá YAMBOOT/MBOO╘á method¼ ì
describeΣ iε thσ followinτ categories.

"HELP THIS-SYS" gives more details of running XSTAM.

:Using CRCK to check file transfers

Whateve≥á methoΣá yo⌡ usσ t∩ transfe≥ file≤ froφá thi≤á systeφ ì
therσ i≤ ß wa∙ yo⌡ caε seσ iµ yo⌡ endeΣ u≡ witΦ ß gooΣ cop∙ oµ ì
the files. It involves comparing CRC checksums of the files.
èT∩á obtaiεá thσ CR├ checksuφ oµ ß filσ oε thσ RCP═ systeφá usσ ì
the XYAM utility. At the XYAM prompt give the command

     CRCK filename

XYA═á wil∞ givσ yo⌡ ß ┤ digi⌠ hexadecima∞ numbe≥ whicΦ i≤á thσ ì
checksum of the file derived using the CCITT polynomial.

T∩ obtaiε thσ CR├ checksuφ a⌠ you≥ enΣ usσ thσ CRC╦ commanΣ iε ì
you≥á cop∙ oµ YA═ o≥ iµ yo⌡ aren'⌠ usinτ YA═ usσ thσá CRCK.CO═ ì
utility«á CRCK.AS═ i≤ alway≤ onlinσ fo≥ dowε loadinτ froφ thi≤ ì
system«á(Thσá CR├ checksuφ produceΣ b∙ CRCK.CO═ i≤ thσ samσ a≤ ì
i≤ produceΣ b∙ thσ CRC╦ functioε iε YAM).

Thσ CRC╦ number≤ fo≥ thσ filσ oε thσ RCP═ systeφ anΣ thσá dowε ì
loadeΣá filσ oε you≥ systeφ shoulΣ bσ identical«á Iµ the∙á arσ ì
not, an error occurred during the file transfer.


Thσá samσ methoΣ caε bσ useΣ t∩ checδ tha⌠ file≤ u≡ loadeΣá t∩ ì
the RCPM system were received correctly.

Somσá oµá thσ morσ recen⌠ Use≥ Grou≡ volume≤á wil∞á havσá CRC╦ ì
file≤ witΦ checksum≤ fo≥ al∞ thσ file≤ oε thσ volumσ containeΣ ì
iεá them«á Iµ yo⌡ havσ t∩ archivσ you≥ owε program≤ it≤ ß gooΣ ì
ideß t∩ pu⌠ ß CR├ checksuφ filσ oε eacΦ archivσ disk¼ wheε yo⌡ ì
neeΣá t∩ acces≤ thσ archivσ file≤ yo⌡ caε easil∙ checδ t∩á seσ ì
iµ thσ file≤ arσ stil∞ intac⌠ beforσ usinτ them«